'Return the model parameters in the form of numpy arrays.
:param graph: tf graph object
:return: model parameters'

def get_parameters(self, graph=None):

    g = (graph if (graph is not None) else self.tf_graph)
    with g.as_default():
        with tf.Session() as self.tf_session:
            self.tf_saver.restore(self.tf_session, self.model_path)
            return {'W': self.W.eval(), 'bh_': self.bh_.eval(), 'bv_': self.bv_.eval()}
