@classmethod
def store_data(cls, name, data):
    """
        Store the attribute in the thread local object if none with the same name exists.
        """
    if hasattr(cls.__locals, name):
        raise AttributeError(
            'Chipmunk can\'t store attribute "%s", it\'s already holding one.'
             % name)
    setattr(cls.__locals, name, data)
