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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 signed(item):
 """ Is any part of the document signed ? :param item: A Samlbase instance :return: True if some part of it is signed """

    if SIG in item.c_children.keys() and item.signature:
        return True
    else:
        for prop in item.c_child_order:
            child = getattr(item, prop, None)
            if isinstance(child, list):
                for chi in child:
                    if signed(chi):
                        return True
            elif child and signed(child):
                return True

    return False