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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 _module_env(self, execution):
 """Set current process environment according to execution `environment` and `modules` """

        env = copy.copy(os.environ)
        try:
            for mod in execution.get('modules') or []:
                Module.load(mod)
            os.environ.update(execution.get('environment') or {})
            yield
        finally:
            os.environ = env