Description:
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It would be nice to have an additional argument (string, defaults to '\') to 'get_declared_classes' to only return the classes inside a certain namespace. An second argument (bool, defaults to false) could be optional to ask if resolution should be recursive to subnamespaces.

Reproduce code:
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Would be something defined as being:

get_declared_namespaces( String $sNamespace = '\', Bool $bRecursive = false);

Expected result:
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List of classes in namespace.

Actual result:
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List of all classes.