'timer ON|OFF: Control printing of time and resource usage after each query
The values displayed are in seconds when shown as floating
point or an absolute count.  Only items that have changed
since starting the query are shown.  On non-Windows platforms
considerably more information can be shown.'

def command_timer(self, cmd):

    if self._boolean_command('timer', cmd):
        try:
            self.get_resource_usage()
        except:
            raise self.Error('Timing    not    supported    by    this    Python    version/platform')
        self.timer = True
    else:
        self.timer = False
