def aimport_module(self, module_name):
        """Import a module, and mark it reloadable

        Returns
        -------
        top_module : module
            The imported module if it is top-level, or the top-level
        top_name : module
            Name of top_module

        """
        self.mark_module_reloadable(module_name)

        import_module(module_name)
        top_name = module_name.split('.')[0]
        top_module = sys.modules[top_name]
        return top_module, top_name