def _gather_mm_scatter(A, B, out, idx_a=None, idx_b=None, idx_c=None):
    r"""Invoke the C API of the gather_mm_scatter operator."""
    _CAPI_DGLKernelGATHERMMSCATTER(
        to_dgl_nd(A),
        to_dgl_nd(B),
        to_dgl_nd_for_write(out),
        to_dgl_nd(idx_a),
        to_dgl_nd(idx_b),
        to_dgl_nd(idx_c),
    )
    return out
Invoke the C API of the gather_mm_scatter operator.
python/dgl/_sparse_ops.py