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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 get_one_required(self, locator):
 """ Gets a required component reference that matches specified locator. :param locator: the locator to find a reference by. :return: a matching component reference. :raises: a [[ReferenceException]] when no references found. """

        components = self.find(locator, True)
        return components[0] if len(components) > 0 else None