def _pump(self):
while (not self._busy) and len(self._queue):<EOL><INDENT>cmd = self._queue.pop(<NUM_LIT:0>)<EOL>self._name = cmd[<NUM_LIT:2>]<EOL>try:<EOL><INDENT>cmd[<NUM_LIT:0>](*cmd[<NUM_LIT:1>])<EOL><DEDENT>except Exception as e:<EOL><INDENT>self.notify('<STR_LIT:error>', exception=e)<EOL>if self._debug:<EOL><INDENT>traceback.print_exc()<EOL><DEDENT><DEDENT><DEDENT>
Attempts to process the next command in the queue if one exists and the
driver is not currently busy.