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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def pyobjc_method_signature(signature_str):
 """ Return a PyObjCMethodSignature object for given signature string. :param signature_str: A byte string containing the type encoding for the method signature :return: A method signature object, assignable to attributes like __block_signature__ :rtype: <type objc._method_signature> """

        _objc_so.PyObjCMethodSignature_WithMetaData.restype = ctypes.py_object
        return _objc_so.PyObjCMethodSignature_WithMetaData(ctypes.create_string_buffer(signature_str), None, False)