code: def _tag_type_to_explicit_implicit(params):
      
  
      if 'tag_type' in params:
          if params['tag_type'] == 'explicit':
              params['explicit'] = (params.get('class', 2), params['tag'])
          elif params['tag_type'] == 'implicit':
              params['implicit'] = (params.get('class', 2), params['tag'])
          del params['tag_type']
          del params['tag']
          if 'class' in params:
              del params['class']
docs: Converts old-style "tag_type" and "tag" params to "explicit" and "implicit"
  
      :param params:
          A dict of parameters to convert from tag_type/tag to explicit/implicit