public static Structure findExistingClassStruct(Function func) {
		Namespace namespace = func.getParentNamespace();
		if (!(namespace instanceof GhidraClass)) {
			return null;
		}
		return findExistingClassStruct((GhidraClass) namespace,
			func.getProgram().getDataTypeManager());
	}
Find the structure data type which corresponds to the specified function's class namespace
within the function's program.

The preferred structure will utilize a namespace-based category path, however,
the match criteria can be fuzzy and relies primarily on the class name.
A properly named class structure must reside within a category whose trailing 
path either matches the class namespace or the class-parent's namespace.  
Preference is given to it residing within the class-parent's namespace.

@param func the function.
@return existing structure whose name matches the specified function's class namespace
or null if not found.
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/listing/VariableUtilities.java