code: def move_tab(self, index_from, index_to):
          
          filename = self.filenames.pop(index_from)
          client = self.clients.pop(index_from)
          self.filenames.insert(index_to, filename)
          self.clients.insert(index_to, client)
          self.update_tabs_text()
          self.sig_update_plugin_title.emit()
docs: Move tab (tabs themselves have already been moved by the tabwidget)