def get_metadata(self, prefix=None):
        return self.manager.get_metadata(self, prefix)
:type train_data: groundhog dataset object
dataset/ETHPy150Open rackspace/pyrax/pyrax/object_storage.py/StorageObject.get_metadata--crossover with--dataset/ETHPy150Open pascanur/GroundHog/groundhog/mainLoop.py/MainLoop.__init__