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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 unparse_signature(signature) :
    "converts a signature from parsed form to string form."
    signature = parse_signature(signature)
    if not isinstance(signature, (tuple, list)) :
        signature = [signature]
    #end if
    return \
        DBUS.Signature("".join(t.signature for t in signature))