def METHOD_NAME(self):
    """Return boolean node array
    True where core node is flooded or self-draining.
    """
    is_core = self._grid.status_at_node == self._grid.BC_NODE_IS_CORE
    if self._depressions_are_handled():
        is_flooded_core = is_core & (
            self._grid.at_node["flood_status_code"] == _FLOODED
        )
    else:
        is_flooded_core = is_core & (
            self._flow_receivers == self._grid.nodes.flatten()
        )
    return np.asarray(is_flooded_core)