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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 map_req(self, requirement):
 """ Maps the name of an Requirement class to the name of the corresponding module in the environment Parameters requirement : Requirement The requirement to map to the name of a module on the system """

        if isinstance(self._packages_map, dict):
            local_name = self._packages_map.get(requirement, requirement.name)
        else:
            local_name = self._packages_map(requirement)
        return local_name