code: def job_priority_index(job_priorities):
      '''This structure helps with finding data from the job priorities table'''
      jp_index = {}
      # Creating this data structure which reduces how many times we iterate through the DB rows
      for jp in job_priorities:
          key = jp.unique_identifier()
  
          # This is guaranteed by a unique composite index for these 3 fields in models.py
          if key in jp_index:
              msg = '"{}" should be a unique job priority and that is unexpected.'.format(key)
              raise DuplicateKeyError(msg)
  
          # (testtype, buildtype, platform)
          jp_index[key] = {'pk': jp.id, 'build_system_type': jp.buildsystem}
  
      return jp_indef job_priority_index(job_priorities):
      '''This structure helps with finding data from the job priorities table'''
      jp_index = {}
      # Creating this data structure which reduces how many times we iterate through the DB rows
      for jp in job_priorities:
          key = jp.unique_identifier()
  
          # This is guaranteed by a unique composite index for these 3 fields in models.py
          if key in jp_index:
              msg = '"{}" should be a unique job priority and that is unexpected.'.format(key)
              raise DuplicateKeyError(msg)
  
          # (testtype, buildtype, platform)
          jp_index[key] = {'pk': jp.id, 'build_system_type': jp.buildsystem}
  
      return jp_index
docs: This structure helps with finding data from the job priorities table