code: def get_var(self, var, info_cb=DEFAULT_MESSAGE_CALLBACK):
      
      return self._simple_command('getvar', arg=var, info_cb=info_cb)
docs: Returns the given variable's definition.
  
      Args:
        var: A variable the bootloader tracks, such as version.
        info_cb: See Download. Usually no messages.
      Returns:
        Value of var according to the current bootloader.