code: def add_bookmark(self, time):
          
          if self.annot is None:  # remove if buttons are disabled
              msg = 'No score file loaded'
              lg.debug(msg)
              error_dialog = QErrorMessage()
              error_dialog.setWindowTitle('Error adding bookmark')
              error_dialog.showMessage(msg)
              error_dialog.exec()
              return
  
          answer = QInputDialog.getText(self, 'New Bookmark',
                                        'Enter bookmark\'s name')
          if answer[1]:
              name = answer[0]
              self.annot.add_bookmark(name, time)
              lg.info('Added Bookmark ' + name + 'at ' + str(time))
  
          self.update_annotations()
docs: Run this function when user adds a new bookmark.
  
          Parameters
          ----------
          time : tuple of float
              start and end of the new bookmark, in s