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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_builtin_function(id_node):
 # type: (Dict[str, Any]) -> bool """ Whether the specified node is a builtin function name identifier. The given identifier should be a child node of NodeType.CALL. """

    # Builtin functions are always IDENTIFIER.
    if NodeType(id_node['type']) is not NodeType.IDENTIFIER:
        return False

    id_value = id_node['value']

    if not is_function_identifier(id_node):
        return False

    # There are difference between a function identifier and variable
    # identifier:
    #
    #   let localtime = 0
    #   echo localtime " => 0
    #   echo localtime() " => 1420011455
    return id_value in BuiltinFunctions