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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_name(self):
 """ The module where this route's view function was defined. """

        if not self.view_func:
            return None
        elif self._controller_cls:
            rv = inspect.getmodule(self._controller_cls).__name__
            return rv
        return inspect.getmodule(self.view_func).__name__