code: def execute_command(self, command, tab=None):
          # TODO DBUS_ONLY
          
          # TODO CONTEXTMENU this has to be rewriten and only serves the
          # dbus interface, maybe this should be moved to dbusinterface.py
          if not self.get_notebook().has_page():
              self.add_tab()
  
          if command[-1] != '\n':
              command += '\n'
  
          terminal = self.get_notebook().get_current_terminal()
          terminal.feed_child(command)
docs: Execute the `command' in the `tab'. If tab is None, the
          command will be executed in the currently selected
          tab. Command should end with '\n', otherwise it will be
          appended to the string.