def _get_n_repr(self, ntid, u):
        """Get node(s) representation of a single node type.

        The returned feature tensor batches multiple node features on the first dimension.

        Parameters
        ----------
        ntid : int
            Node type id.
        u : node, container or tensor
            The node(s).

        Returns
        -------
        dict
            Representation dict from feature name to feature tensor.
        """
        if is_all(u):
            return self._node_frames[ntid]
        else:
            u = utils.prepare_tensor(self, u, "u")
            return self._node_frames[ntid].subframe(u)
Get node(s) representation of a single node type.

        The returned feature tensor batches multiple node features on the first dimension.

        Parameters
        ----------
        ntid : int
            Node type id.
        u : node, container or tensor
            The node(s).

        Returns
        -------
        dict
            Representation dict from feature name to feature tensor.
        
python/dgl/heterograph.py