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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 close_interface(self, client_id, conn_string, interface):
 """Close a device interface on behalf of a client. See :meth:`AbstractDeviceAdapter.close_interface`. Args: client_id (str):
 The client we are working for. conn_string (str):
 A connection string that will be passed to the underlying device adapter. interface (str):
 The name of the interface to close. Raises: DeviceServerError: There is an issue with your client_id such as not being connected to the device. DeviceAdapterError: The adapter had an issue closing the interface. """


        conn_id = self._client_connection(client_id, conn_string)

        await self.adapter.close_interface(conn_id, interface)
        self._hook_close_interface(conn_string, interface, client_id)