def extend(self, feats, feat_scheme=None):
        """Extend the feature data.

        The operation triggers index selection.

        Parameters
        ----------
        feats : Tensor
            The new features.
        feat_scheme : Scheme, optional
            The scheme
        """
        if feat_scheme is None:
            feat_scheme = infer_scheme(feats)

        if feat_scheme != self.scheme:
            raise DGLError(
                "Cannot update column of scheme %s using feature of scheme %s."
                % (feat_scheme, self.scheme)
            )

        self.data = F.cat([self.data, feats], dim=0)
Extend the feature data.

        The operation triggers index selection.

        Parameters
        ----------
        feats : Tensor
            The new features.
        feat_scheme : Scheme, optional
            The scheme
        
python/dgl/frame.py