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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 update(self, module_name=None):
 """ Update a module. If module_name is supplied the module of that name is updated. Otherwise the module calling is updated. """

        if not module_name:
            return self._module.force_update()
        else:
            module_info = self._get_module_info(module_name)
            if module_info:
                module_info["module"].force_update()