code: def combine_focus_with_prev(self):
          
  
          above, ignore = self.get_prev(self.focus)
          if above is None:
              # already at the top
              return
  
          focus = self.lines[self.focus]
          above.set_edit_pos(len(above.edit_text))
          above.set_edit_text(above.edit_text + focus.edit_text)
          del self.lines[self.focus]
          self.focus -= 1
docs: Combine the focus edit widget with the one above.