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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 add_xml_declaration(fn):
 """ Decorator to add header with XML version declaration to output from FN. """

    @wraps(fn)
    def add_xml_declaration_decorator(*args, **kwargs):
        return '<?xml version="1.0" encoding="UTF-8"?>\n\n' + fn(
            *args,
            **kwargs
        )

    return add_xml_declaration_decorator