code: def generate_labels(items, prefix='__'):
      
      return ['{}{}'.format(prefix, n) for n in range(len(items))]
docs: Given an array of items (e.g. events, intervals), create a synthetic label
      for each event of the form '(label prefix)(item number)'
  
      Parameters
      ----------
      items : list-like
          A list or array of events or intervals
      prefix : str
          This prefix will be prepended to all synthetically generated labels
          (Default value = '__')
  
      Returns
      -------
      labels : list of str
          Synthetically generated labels