True if given trees share the same structure of powernodes,
    independently of (power)node names,
    and same edge topology between (power)nodes.

def same_network(atree, btree) -> bool:
    """True if given trees share the same structure of powernodes,
    independently of (power)node names,
    and same edge topology between (power)nodes.

    """
    return same_hierarchy(atree, btree) and same_topology(atree, btree)