PHP Phan\Log类代码示例

 /**
  * Check to see if the given Clazz is a duplicate
  *
  * @return null
  */
 public static function analyzeDuplicateClass(CodeBase $code_base, Clazz $clazz)
 {
     // Determine if its a duplicate by looking to see if
     // the FQSEN is suffixed with an alternate ID.
     if (!$clazz->getFQSEN()->isAlternate()) {
         return;
     }
     $original_fqsen = $clazz->getFQSEN()->getCanonicalFQSEN();
     if (!$code_base->hasClassWithFQSEN($original_fqsen)) {
         // If there's a missing class we'll catch that
         // elsewhere
         return;
     }
     // Get the original class
     $original_class = $code_base->getClassByFQSEN($original_fqsen);
     // Check to see if the original definition was from
     // an internal class
     if ($original_class->isInternal()) {
         Log::err(Log::EREDEF, "{$clazz} defined at " . "{$clazz->getContext()->getFile()}:{$clazz->getContext()->getLineNumberStart()} " . "was previously defined as {$original_class} internally", $clazz->getContext()->getFile(), $clazz->getContext()->getLineNumberStart());
         // Otherwise, print the coordinates of the original
         // definition
     } else {
         Log::err(Log::EREDEF, "{$clazz} defined at " . "{$clazz->getContext()->getFile()}:{$clazz->getContext()->getLineNumberStart()} " . "was previously defined as {$original_class} at " . "{$original_class->getContext()->getFile()}:{$original_class->getContext()->getLineNumberStart()}", $clazz->getContext()->getFile(), $clazz->getContext()->getLineNumberStart());
     }
     return;
 }

 /**
  * Check to see if the given Clazz is a duplicate
  *
  * @return null
  */
 public static function analyzeParentConstructorCalled(CodeBase $code_base, Clazz $clazz)
 {
     // Only look at classes configured to require a call
     // to its parent constructor
     if (!in_array($clazz->getName(), Config::get()->parent_constructor_required)) {
         return;
     }
     // Don't worry about internal classes
     if ($clazz->isInternal()) {
         return;
     }
     // Don't worry if there's no parent class
     if (!$clazz->hasParentClassFQSEN()) {
         return;
     }
     if (!$code_base->hasClassWithFQSEN($clazz->getParentClassFQSEN())) {
         // This is an error, but its caught elsewhere. We'll
         // just roll through looking for other errors
         return;
     }
     $parent_clazz = $code_base->getClassByFQSEN($clazz->getParentClassFQSEN());
     if (!$parent_clazz->isAbstract() && !$clazz->getIsParentConstructorCalled()) {
         Log::err(Log::ETYPE, "{$clazz->getFQSEN()} extends {$parent_clazz->getFQSEN()} but doesn't call parent::__construct()", $clazz->getContext()->getFile(), $clazz->getContext()->getLineNumberStart());
     }
 }

 /**
  * @return bool
  * True if the FQSEN exists. If not, a log line is emitted
  */
 private static function fqsenExistsForClass(FQSEN $fqsen, CodeBase $code_base, Clazz $clazz, string $message_template) : bool
 {
     if (!$code_base->hasClassWithFQSEN($fqsen)) {
         Log::err(Log::EUNDEF, sprintf($message_template, $fqsen), $clazz->getContext()->getFile(), $clazz->getContext()->getLineNumberStart());
         return false;
     }
     return true;
 }

 /**
  * @return bool
  * True if the FQSEN exists. If not, a log line is emitted
  */
 private static function fqsenExistsForClass(FQSEN $fqsen, CodeBase $code_base, Clazz $clazz) : bool
 {
     if (!$code_base->hasClassWithFQSEN($fqsen)) {
         Log::err(Log::EUNDEF, "Trying to inherit from unknown class {$fqsen}", $clazz->getContext()->getFile(), $clazz->getContext()->getLineNumberStart());
         return false;
     }
     return true;
 }

 /**
  * Check to see if the given Clazz is a duplicate
  *
  * @return null
  */
 public static function analyzePropertyTypes(CodeBase $code_base, Clazz $clazz)
 {
     foreach ($clazz->getPropertyList($code_base) as $property) {
         $union_type = $property->getUnionType();
         // Look at each type in the parameter's Union Type
         foreach ($union_type->getTypeList() as $type) {
             // If its a native type or a reference to
             // self, its OK
             if ($type->isNativeType() || $type->isSelfType()) {
                 continue;
             }
             // Otherwise, make sure the class exists
             $type_fqsen = $type->asFQSEN();
             if (!$code_base->hasClassWithFQSEN($type_fqsen)) {
                 Log::err(Log::EUNDEF, "property of undeclared type {$type_fqsen}", $property->getContext()->getFile(), $property->getContext()->getLineNumberStart());
             }
         }
     }
 }

 /**
  * Check to see if the given Clazz is a duplicate
  *
  * @return null
  */
 public static function analyzeDuplicateFunction(CodeBase $code_base, Method $method)
 {
     $fqsen = $method->getFQSEN();
     if (!$fqsen->isAlternate()) {
         return;
     }
     $original_fqsen = $fqsen->getCanonicalFQSEN();
     if (!$code_base->hasMethod($original_fqsen)) {
         return;
     }
     $original_method = $code_base->getMethod($original_fqsen);
     $method_name = $method->getName();
     if ('internal' === $original_method->getContext()->getFile()) {
         // If its in an conditional and the original is an
         // internal method, presume its all OK.
         if ($method->getContext()->getIsConditional()) {
             return;
         }
         Log::err(Log::EREDEF, "Function {$method_name} defined at {$method->getContext()->getFile()}:{$method->getContext()->getLineNumberStart()} was previously defined internally", $method->getContext()->getFile(), $method->getContext()->getLineNumberStart());
     } else {
         Log::err(Log::EREDEF, "Function {$method_name} defined at {$method->getContext()->getFile()}:{$method->getContext()->getLineNumberStart()} was previously defined at {$original_method->getContext()->getFile()}:{$original_method->getContext()->getLineNumberStart()}", $method->getContext()->getFile(), $method->getContext()->getLineNumberStart());
     }
 }

 /**
  * @param Node $node
  * A node of the type indicated by the method name that we'd
  * like to figure out the type that it produces.
  *
  * @return string
  * The class name represented by the given call
  */
 public function visitNew(Node $node) : string
 {
     // Things of the form `new $class_name();`
     if ($node->children['class']->kind == \ast\AST_VAR) {
         return '';
     }
     // Things of the form `new $method->name()`
     if ($node->children['class']->kind !== \ast\AST_NAME) {
         return '';
     }
     $class_name = $node->children['class']->children['name'];
     if (!in_array($class_name, ['self', 'static', 'parent'])) {
         return AST::qualifiedName($this->context, $node->children['class']);
     }
     if (!$this->context->isInClassScope()) {
         Log::err(Log::ESTATIC, "Cannot access {$class_name}:: when no class scope is active", $this->context->getFile(), $node->lineno);
         return '';
     }
     if ($class_name == 'static') {
         return (string) $this->context->getClassFQSEN();
     }
     if ($class_name == 'self') {
         if ($this->context->isGlobalScope()) {
             assert(false, "Unimplemented branch is required for {$this->context}");
         } else {
             return (string) $this->context->getClassFQSEN();
         }
     }
     if ($class_name == 'parent') {
         $clazz = $this->context->getClassInScope($this->code_base);
         if (!$clazz->hasParentClassFQSEN()) {
             return '';
         }
         return (string) $clazz->getParentClassFQSEN();
     }
     return '';
 }

 /**
  * Check to see if the given Clazz is a duplicate
  *
  * @return null
  */
 public static function analyzeElementReferenceCounts(CodeBase $code_base, TypedStructuralElement $element)
 {
     // Don't worry about internal elements
     if ($element->getContext()->isInternal()) {
         return;
     }
     if ($element->getReferenceCount($code_base) < 1) {
         if ($element instanceof Addressable) {
             Log::err(Log::ENOOP, "{$element->getFQSEN()} may have zero references", $element->getContext()->getFile(), $element->getContext()->getLineNumberStart());
         } else {
             Log::err(Log::ENOOP, "{$element} may have zero references", $element->getContext()->getFile(), $element->getContext()->getLineNumberStart());
         }
     }
 }

 /**
  * @return bool
  * False if the class name doesn't point to a known class
  */
 private function classExistsOrIsNative(Node $node) : bool
 {
     if ($this->classExists()) {
         return true;
     }
     $type = UnionType::fromStringInContext($this->class_name, $this->context);
     if ($type->isNativeType()) {
         return true;
     }
     Log::err(Log::EUNDEF, "reference to undeclared class {$this->class_fqsen}", $this->context->getFile(), $node->lineno);
     return false;
 }

 /**
  * Create and read command line arguments, configuring
  * \Phan\Config as a side effect.
  */
 public function __construct()
 {
     global $argv;
     // file_put_contents('/tmp/file', implode("\n", $argv));
     // Parse command line args
     // still available: g,j,k,n,t,u,v,w,z
     $opts = getopt("f:m:o:c:aeqbrpid:s:3:y:l:xh::", ['fileset:', 'output-mode:', 'output:', 'parent-constructor-required:', 'expanded-dependency-list', 'dump-ast', 'quick', 'backward-compatibility-checks', 'reanalyze-file-list', 'progress-bar', 'ignore-undeclared', 'project-root-directory:', 'state-file:', 'exclude-directory-list:', 'minimum-severity:', 'directory:', 'dead-code-detection', 'help']);
     // Determine the root directory of the project from which
     // we root all relative paths passed in as args
     Config::get()->setProjectRootDirectory($opts['d'] ?? getcwd());
     // Now that we have a root directory, attempt to read a
     // configuration file `.phan/config.php` if it exists
     $this->maybeReadConfigFile();
     foreach ($opts ?? [] as $key => $value) {
         switch ($key) {
             case 'h':
             case 'help':
                 $this->usage();
                 break;
             case 'f':
             case 'fileset':
                 $file_list = is_array($value) ? $value : [$value];
                 foreach ($file_list as $file_name) {
                     if (is_file($file_name) && is_readable($file_name)) {
                         $this->file_list = array_merge($this->file_list, file($file_name, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES));
                     } else {
                         error_log("Unable to read file {$file_name}");
                     }
                 }
                 break;
             case 'l':
             case 'directory':
                 $directory_list = is_array($value) ? $value : [$value];
                 foreach ($directory_list as $directory_name) {
                     $this->file_list = array_merge($this->file_list, $this->directoryNameToFileList($directory_name));
                 }
                 break;
             case 'm':
             case 'output-mode':
                 if (!in_array($value, ['text', 'codeclimate'])) {
                     $this->usage("Unknown output mode: {$value}");
                 }
                 Log::setOutputMode($value);
                 break;
             case 'c':
             case 'parent-constructor-required':
                 Config::get()->parent_constructor_required = explode(',', $value);
                 break;
             case 'q':
             case 'quick':
                 Config::get()->quick_mode = true;
                 break;
             case 'b':
             case 'backward-compatibility-checks':
                 Config::get()->backward_compatibility_checks = true;
                 break;
             case 'p':
             case 'progress-bar':
                 Config::get()->progress_bar = true;
                 break;
             case 'a':
             case 'dump-ast':
                 Config::get()->dump_ast = true;
                 break;
             case 'e':
             case 'expanded-dependency-list':
                 Config::get()->expanded_dependency_list = true;
                 break;
             case 'o':
             case 'output':
                 Log::setFilename($value);
                 break;
             case 'i':
             case 'ignore-undeclared':
                 Log::setOutputMask(Log::getOutputMask() ^ Issue::CATEGORY_UNDEFINED);
                 break;
             case '3':
             case 'exclude-directory-list':
                 Config::get()->exclude_analysis_directory_list = explode(',', $value);
                 break;
             case 's':
             case 'state-file':
                 Config::get()->stored_state_file_path = $value;
                 break;
             case 'r':
             case 'reanalyze-file-list':
                 Config::get()->reanalyze_file_list = true;
                 break;
             case 'y':
             case 'minimum-severity':
                 Config::get()->minimum_severity = $value;
                 break;
             case 'd':
             case 'project-root-directory':
                 // We handle this flag before parsing options so
                 // that we can get the project root directory to
//.........这里部分代码省略.........

 /**
  * @param Node $node
  * A node of the type indicated by the method name that we'd
  * like to figure out the type that it produces.
  *
  * @return string
  * The class name represented by the given call
  */
 public function visitNew(Node $node) : string
 {
     // Things of the form `new $class_name();`
     if ($node->children['class']->kind == \ast\AST_VAR) {
         return '';
     }
     // Anonymous class
     // $v = new class { ... }
     if ($node->children['class']->kind == \ast\AST_CLASS && $node->children['class']->flags & \ast\flags\CLASS_ANONYMOUS) {
         return (new ContextNode($this->code_base, $this->context, $node->children['class']))->getUnqualifiedNameForAnonymousClass();
     }
     // Things of the form `new $method->name()`
     if ($node->children['class']->kind !== \ast\AST_NAME) {
         return '';
     }
     $class_name = $node->children['class']->children['name'];
     if (!in_array($class_name, ['self', 'static', 'parent'])) {
         return (string) UnionTypeVisitor::unionTypeFromClassNode($this->code_base, $this->context, $node->children['class']);
     }
     if (!$this->context->isInClassScope()) {
         Log::err(Log::ESTATIC, "Cannot access {$class_name}:: when no class scope is active", $this->context->getFile(), $node->lineno);
         return '';
     }
     if ($class_name == 'static') {
         return (string) $this->context->getClassFQSEN();
     }
     if ($class_name == 'self') {
         if ($this->context->isGlobalScope()) {
             assert(false, "Unimplemented branch is required for {$this->context}");
         } else {
             return (string) $this->context->getClassFQSEN();
         }
     }
     if ($class_name == 'parent') {
         $clazz = $this->context->getClassInScope($this->code_base);
         if (!$clazz->hasParentClassFQSEN()) {
             return '';
         }
         return (string) $clazz->getParentClassFQSEN();
     }
     return '';
 }

 private function visitClassNode(Node $node) : UnionType
 {
     // Things of the form `new $class_name();`
     if ($node->kind == \ast\AST_VAR) {
         return new UnionType();
     }
     // Anonymous class of form `new class { ... }`
     if ($node->kind == \ast\AST_CLASS && $node->flags & \ast\flags\CLASS_ANONYMOUS) {
         // Generate a stable name for the anonymous class
         $anonymous_class_name = (new ContextNode($this->code_base, $this->context, $node))->getUnqualifiedNameForAnonymousClass();
         // Turn that into a fully qualified name
         $fqsen = FullyQualifiedClassName::fromStringInContext($anonymous_class_name, $this->context);
         // Turn that into a union type
         return Type::fromFullyQualifiedString((string) $fqsen)->asUnionType();
     }
     // Things of the form `new $method->name()`
     if ($node->kind !== \ast\AST_NAME) {
         return new UnionType();
     }
     // Get the name of the class
     $class_name = $node->children['name'];
     // If this is a straight-forward class name, recurse into the
     // class node and get its type
     if (!Type::isSelfTypeString($class_name)) {
         // TODO: does anyone else call this method?
         return self::unionTypeFromClassNode($this->code_base, $this->context, $node);
     }
     // This is a self-referential node
     if (!$this->context->isInClassScope()) {
         Log::err(Log::ESTATIC, "Cannot access {$class_name} when not in a class scope", $this->context->getFile(), $node->lineno);
         return new UnionType();
     }
     // Reference to a parent class
     if ($class_name === 'parent') {
         $class = $this->context->getClassInScope($this->code_base);
         if (!$class->hasParentClassFQSEN()) {
             Log::err(Log::ESTATIC, "Reference to parent of parentless class {$class->getFQSEN()}", $this->context->getFile(), $node->lineno);
             return new UnionType();
         }
         return Type::fromFullyQualifiedString((string) $class->getParentClassFQSEN())->asUnionType();
     }
     return Type::fromFullyQualifiedString((string) $this->context->getClassFQSEN())->asUnionType();
 }

 /**
  * @param Node $node
  * A node to check types on
  *
  * @return UnionType
  * The resulting type(s) of the binary operation
  */
 public function visitBinaryAdd(Node $node) : UnionType
 {
     $left = UnionType::fromNode($this->context, $this->code_base, $node->children['left']);
     $right = UnionType::fromNode($this->context, $this->code_base, $node->children['right']);
     // fast-track common cases
     if ($left->isType(IntType::instance()) && $right->isType(IntType::instance())) {
         return IntType::instance()->asUnionType();
     }
     if (($left->isType(IntType::instance()) || $left->isType(FloatType::instance())) && ($right->isType(IntType::instance()) || $right->isType(FloatType::instance()))) {
         return FloatType::instance()->asUnionType();
     }
     $left_is_array = !empty($left->genericArrayElementTypes()) && empty($left->nonGenericArrayTypes());
     $right_is_array = !empty($right->genericArrayElementTypes()) && empty($right->nonGenericArrayTypes());
     if ($left_is_array && !$right->canCastToUnionType(ArrayType::instance()->asUnionType())) {
         Log::err(Log::ETYPE, "invalid operator: left operand is array and right is not", $this->context->getFile(), $node->lineno);
         return new UnionType();
     } else {
         if ($right_is_array && !$left->canCastToUnionType(ArrayType::instance()->asUnionType())) {
             Log::err(Log::ETYPE, "invalid operator: right operand is array and left is not", $this->context->getFile(), $node->lineno);
             return new UnionType();
         } else {
             if ($left_is_array || $right_is_array) {
                 // If it is a '+' and we know one side is an array
                 // and the other is unknown, assume array
                 return ArrayType::instance()->asUnionType();
             }
         }
     }
     return new UnionType([IntType::instance(), FloatType::instance()]);
 }

 /**
  * Check to see if the given Clazz is a duplicate
  *
  * @param Method $method
  * The method we're analyzing arguments for
  *
  * @param Node $node
  * The node holding the method call we're looking at
  *
  * @param Context $context
  * The context in which we see the call
  *
  * @param CodeBase $code_base
  *
  * @return null
  *
  * @see \Phan\Deprecated\Pass2::arg_check
  * Formerly `function arg_check`
  */
 private static function analyzeInternalArgumentType(Method $method, Node $node, Context $context, CodeBase $code_base)
 {
     $arglist = $node->children['args'];
     $argcount = count($arglist->children);
     switch ($method->getName()) {
         case 'join':
         case 'implode':
             // (string glue, array pieces),
             // (array pieces, string glue) or
             // (array pieces)
             if ($argcount == 1) {
                 self::analyzeNodeUnionTypeCast($arglist->children[0], $context, $code_base, ArrayType::instance()->asUnionType(), "arg#1(pieces) is %s but {$method->getFQSEN()}() takes array when passed only 1 arg");
                 return;
             } else {
                 if ($argcount == 2) {
                     $arg1_type = UnionType::fromNode($context, $code_base, $arglist->children[0]);
                     $arg2_type = UnionType::fromNode($context, $code_base, $arglist->children[1]);
                     if ((string) $arg1_type == 'array') {
                         if (!$arg1_type->canCastToUnionType(StringType::instance()->asUnionType())) {
                             Log::err(Log::EPARAM, "arg#2(glue) is {$arg2_type} but {$method->getFQSEN()}() takes string when arg#1 is array", $context->getFile(), $context->getLineNumberStart());
                         }
                     } else {
                         if ((string) $arg1_type == 'string') {
                             if (!$arg2_type->canCastToUnionType(ArrayType::instance()->asUnionType())) {
                                 Log::err(Log::EPARAM, "arg#2(pieces) is {$arg2_type} but {$method->getFQSEN()}() takes array when arg#1 is string", $context->getFile(), $context->getLineNumberStart());
                             }
                         }
                     }
                     return;
                 }
             }
             // Any other arg counts we will let the regular
             // checks handle
             break;
         case 'array_udiff':
         case 'array_diff_uassoc':
         case 'array_uintersect_assoc':
         case 'array_intersect_ukey':
             if ($argcount < 3) {
                 Log::err(Log::EPARAM, "call with {$argcount} arg(s) to {$method->getFQSEN()}() which requires {$method->getNumberOfRequiredParameters()} arg(s)", $context->getFile(), $context->getLineNumberStart());
                 return;
             }
             self::analyzeNodeUnionTypeCast($arglist->children[$argcount - 1], $context, $code_base, CallableType::instance()->asUnionType(), "The last argument to {$method->getFQSEN()} must be a callable");
             for ($i = 0; $i < $argcount - 1; $i++) {
                 self::analyzeNodeUnionTypeCast($arglist->children[$i], $context, $code_base, CallableType::instance()->asUnionType(), "arg#" . ($i + 1) . " is %s but {$method->getFQSEN()}() takes array");
             }
             return;
         case 'array_diff_uassoc':
         case 'array_uintersect_uassoc':
             if ($argcount < 4) {
                 Log::err(Log::EPARAM, "call with {$argcount} arg(s) to {$method->getFQSEN()}() which requires {$method->getNumberOfRequiredParameters()} arg(s)", $context->getFile(), $context->getLineNumberStart());
                 return;
             }
             // The last 2 arguments must be a callable and there
             // can be a variable number of arrays before it
             self::analyzeNodeUnionTypeCast($arglist->children[$argcount - 1], $context, $code_base, CallableType::instance()->asUnionType(), "The last argument to {$method->getFQSEN()} must be a callable");
             self::analyzeNodeUnionTypeCast($arglist->children[$argcount - 2], $context, $code_base, CallableType::instance()->asUnionType(), "The second last argument to {$method->getFQSEN()} must be a callable");
             for ($i = 0; $i < $argcount - 2; $i++) {
                 self::analyzeNodeUnionTypeCast($arglist->children[$i], $context, $code_base, ArrayType::instance()->asUnionType(), "arg#" . ($i + 1) . " is %s but {$method->getFQSEN()}() takes array");
             }
             return;
         case 'strtok':
             // (string str, string token) or (string token)
             if ($argcount == 1) {
                 // If we have just one arg it must be a string token
                 self::analyzeNodeUnionTypeCast($arglist->children[0], $context, $code_base, ArrayType::instance()->asUnionType(), "arg#1(token) is %s but {$method->getFQSEN()}() takes string when passed only one arg");
             }
             // The arginfo check will handle the other case
             break;
         case 'min':
         case 'max':
             if ($argcount == 1) {
                 // If we have just one arg it must be an array
                 if (!self::analyzeNodeUnionTypeCast($arglist->children[0], $context, $code_base, ArrayType::instance()->asUnionType(), "arg#1(values) is %s but {$method->getFQSEN()}() takes array when passed only one arg")) {
                     return;
                 }
             }
             // The arginfo check will handle the other case
             break;
         default:
             break;
//.........这里部分代码省略.........

 /**
  * @param Node $node
  * A node of the type indicated by the method name that we'd
  * like to figure out the type that it produces.
  *
  * @return string
  * The class name represented by the given call
  */
 public function visitProp(Node $node) : string
 {
     if (!($node->children['expr']->kind == \ast\AST_VAR && !$node->children['expr']->children['name'] instanceof Node)) {
         return '';
     }
     // $var->prop->method()
     $var = $node->children['expr'];
     $class = null;
     if ($var->children['name'] == 'this') {
         // If we're not in a class scope, 'this' won't work
         if (!$this->context->isInClassScope()) {
             Log::err(Log::ESTATIC, 'Using $this when not in object context', $this->context->getFile(), $node->lineno);
             return '';
         }
         // $this->$node->method()
         if ($node->children['prop'] instanceof Node) {
             // Too hard. Giving up.
             return '';
         }
         $class = $this->context->getClassInScope($this->code_base);
     } else {
         // Get the list of viable class types for the
         // variable
         $union_type = AST::varUnionType($this->context, $var)->nonNativeTypes()->nonGenericArrayTypes();
         if ($union_type->isEmpty()) {
             return '';
         }
         $class_fqsen = $union_type->head()->asFQSEN();
         if (!$this->code_base->hasClassWithFQSEN($class_fqsen)) {
             return '';
         }
         $class = $this->code_base->getClassByFQSEN($class_fqsen);
     }
     $property_name = $node->children['prop'];
     if (!$class->hasPropertyWithName($this->code_base, $property_name)) {
         // If we can't find the property, there's
         // no type. Thie issue should be caught
         // elsewhere.
         return '';
     }
     try {
         $property = $class->getPropertyByNameInContext($this->code_base, $property_name, $this->context);
     } catch (AccessException $exception) {
         Log::err(Log::EACCESS, $exception->getMessage(), $this->context->getFile(), $node->lineno);
         return '';
     }
     $union_type = $property->getUnionType()->nonNativeTypes();
     if ($union_type->isEmpty()) {
         // If we don't have a type on the property we
         // can't figure out the class type.
         return '';
     } else {
         // Return the first type on the property
         // that could be a reference to a class
         return (string) $union_type->head()->asFQSEN();
     }
     // No such property was found, or none were classes
     // that could be found
     return '';
 }