code: def keypress(self, size, key):
          
          key = super().keypress(size, key)
          num_tabs = len(self._widgets)
          if key == self._keys['prev_tab']:
              self._tab_index = (self._tab_index - 1) % num_tabs
              self._update_tabs()
          elif key == self._keys['next_tab']:
              self._tab_index = (self._tab_index + 1) % num_tabs
              self._update_tabs()
          elif key == self._keys['close_tab']:
              # Don't allow closing the Conversations tab
              if self._tab_index > 0:
                  curr_tab = self._widgets[self._tab_index]
                  self._widgets.remove(curr_tab)
                  del self._widget_title[curr_tab]
                  self._tab_index -= 1
                  self._update_tabs()
          else:
              return key
docs: Handle keypresses for changing tabs.