code: def update_descriptor_le(self, lineedit, tf):
          
          if tf:
              descriptor = tf.descriptor
              lineedit.setText(descriptor)
          else:
              lineedit.setText("")
docs: Update the given line edit to show the descriptor that is stored in the index
  
          :param lineedit: the line edit to update with the descriptor
          :type lineedit: QLineEdit
          :param tf: the selected taskfileinfo
          :type tf: :class:`TaskFileInfo` | None
          :returns: None
          :rtype: None
          :raises: None