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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 is_list(node):
 """Does the node represent a list literal?"""

    return (isinstance(node, Node)
            and len(node.children) > 1
            and isinstance(node.children[0], Leaf)
            and isinstance(node.children[-1], Leaf)
            and node.children[0].value == u"["
            and node.children[-1].value == u"]")