docs: def append(self, decoration):
          """
          Adds a text decoration on a CodeEdit instance
  
          :param decoration: Text decoration to add
          :type decoration: pyqode.core.api.TextDecoration
          """
          if decoration not in self._decorations:
              self._decorations.append(decoration)
              self._decorations = sorted(
                  self._decorations, key=lambda sel: sel.draw_order)
              self.editor.setExtraSelections(self._decorations)
              return True
          return False