docs: def update_metadata_filters(metadata, jupyter_md, cell_metadata):
      """Update or set the notebook and cell metadata filters"""
  
      cell_metadata = [m for m in cell_metadata if m not in ['language', 'magic_args']]
  
      if 'cell_metadata_filter' in metadata.get('jupytext', {}):
          metadata_filter = metadata_filter_as_dict(metadata.get('jupytext', {})['cell_metadata_filter'])
          if isinstance(metadata_filter.get('excluded'), list):
              metadata_filter['excluded'] = [key for key in metadata_filter['excluded'] if key not in cell_metadata]
          metadata_filter.setdefault('additional', [])
          if isinstance(metadata_filter.get('additional'), list):
              for key in cell_metadata:
                  if key not in metadata_filter['additional']:
                      metadata_filter['additional'].append(key)
          metadata.setdefault('jupytext', {})['cell_metadata_filter'] = metadata_filter_as_string(metadata_filter)
  
      if not jupyter_md:
          # Set a metadata filter equal to the current metadata in script
          cell_metadata = {'additional': cell_metadata, 'excluded': 'all'}
          metadata.setdefault('jupytext', {})['notebook_metadata_filter'] = '-all'
          metadata.setdefault('jupytext', {})['cell_metadata_filter'] = metadata_filter_as_string(cell_metadata)