def __init__(self, options, serialized_options, options_class_name):
    """Initialize the descriptor given its options message and the name of the
    class of the options message. The name of the class is required in case
    the options message is None and has to be created.
    """
    self._options = options
    self._options_class_name = options_class_name
    self._serialized_options = serialized_options

    # Does this descriptor have non-default options?
    self.has_options = (options is not None) or (serialized_options is not None)
Initialize the descriptor given its options message and the name of the
    class of the options message. The name of the class is required in case
    the options message is None and has to be created.
    
deps/protobuf/python/google/protobuf/descriptor.py