def METHOD_NAME(self):
    """Convert the node to JSON.
    Creates a dictionary object of the node conforming to the JSON Graph Format.
    Returns:
        dictionary      the node as dictionary ready to serialize
    """
    json = {Node.ID: self._id}
    if self._label != None:
        json[Node.LABEL] = self._label
    if self._metadata != None:
        json[Node.METADATA] = self._metadata
    return json