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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 unmap_trigger(library, session, trigger_source, trigger_destination):
 """Undo a previous map from the specified trigger source line to the specified destination line. Corresponds to viUnmapTrigger function of the VISA library. :param library: the visa library wrapped by ctypes. :param session: Unique logical identifier to a session. :param trigger_source: Source line used in previous map. (Constants.TRIG*) :param trigger_destination: Destination line used in previous map. (Constants.TRIG*) :return: return value of the library call. :rtype: :class:`pyvisa.constants.StatusCode` """

    return library.viUnmapTrigger(session, trigger_source, trigger_destination)