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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 _locate(self, name):
 """ Gets a dependency locator by its name. :param name: the name of the dependency to locate. :return: the dependency locator or null if locator was not configured. """

        if name == None:
            raise Exception("Dependency name cannot be null")
        if self._references == None:
            raise Exception("References shall be set")
        
        return self._dependencies.get(name)