old_contents: def clean(record):
      if record.bibjson().get_journal_license():
          record.bibjson().remove_journal_license()
      return record
  
new_contents: def clean(record):
      if record.bibjson().get_journal_license():
          record.bibjson().remove_journal_licences()
      return record
  
subject: Fix another typo in migration