docs: def get_metadata(ident_hash):
      """Return the dictionary of metadata from the database.
      This data is keyed using the cnx-epub data structure.
  
      """
      id, version = get_id_n_version(ident_hash)
  
      stmt = _get_sql('get-metadata.sql')
      args = dict(id=id, version=version)
  
      # FIXME The license_url and license_text metadata attributes need to
      # change to a License structure similar to what is used in cnx-authoring.
  
      with db_connect() as db_conn:
          with db_conn.cursor() as cursor:
              cursor.execute(stmt, args)
              try:
                  metadata = cursor.fetchone()[0]
              except TypeError:
                  raise NotFound(ident_hash)
      return metadata