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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 put(self, locator = None, component = None):
 """ Puts a new reference into this reference map. :param locator: a component reference to be added. :param component: a locator to find the reference by. """

        if component == None:
            raise Exception("Component cannot be null")

        self._lock.acquire()
        try:
            self._references.append(Reference(locator, component))
        finally:
            self._lock.release()