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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:
 async def terminate_vm(self, preset, vm_id):
 """ Discard vm in specified preset :arg string preset: preset name :arg int vm_id: Virtual Machine id :return: 'OK' Sample response: ``OK`` """

        vmshepherd = self.request.app.vmshepherd
        preset = vmshepherd.preset_manager.get_preset(preset)
        await preset.iaas.terminate_vm(vm_id)
        return 'OK'