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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_group_node_size(node):
 """ Shared getter for AddrmapNode and RegfileNode's "size" property """

    # After structural placement, children are sorted
    if( not node.inst.children
        or (not isinstance(node.inst.children[-1], comp.AddressableComponent))
    ):
        # No addressable child exists.
        return 0

    # Current node's size is based on last child
    last_child_node = Node._factory(node.inst.children[-1], node.env, node)
    return(
        last_child_node.inst.addr_offset
        + last_child_node.total_size
    )