def forward(self, feat, lengths):
        """
        Compute an Induced Set Attention Block.

        Parameters
        ----------
        feat : torch.Tensor
            The input feature.
        lengths : list
            The array of node numbers, used to segment feat tensor.

        Returns
        -------
        torch.Tensor
            The output feature
        """
        batch_size = len(lengths)
        query = self.inducing_points.repeat(batch_size, 1)
        memory = self.mha[0](query, feat, [self.m] * batch_size, lengths)
        return self.mha[1](feat, memory, lengths, [self.m] * batch_size)

        Compute an Induced Set Attention Block.

        Parameters
        ----------
        feat : torch.Tensor
            The input feature.
        lengths : list
            The array of node numbers, used to segment feat tensor.

        Returns
        -------
        torch.Tensor
            The output feature
        
python/dgl/nn/pytorch/glob.py