Some ideas:

• PostsubmitService
  • addCommits
  • addPullRequest
• PresubmitService
  • cancelPreSubmitTargets
  • triggerPresubmitTargets
  • (Private) _closeCiYamlCheckRun
• MergeQueueService
  • triggerMergeGroupTargets
  • (Private) _getMergeGroupTargetsForStage
  • (Private) _getMergeGroupTargets
  • cancelDestroyedMergeGroupTargets
  • lockMergeGroupChecks
  • unlockMergeQueueGuard
  • failGuardForMergeGroup
• CheckRunService
  • processCheckRun
  • processCheckRunCompletion
  • checkRunFromString (??? TBD)
• Misc
  • (Private) _filterTargets
  • (Private) _getPresubmitTargets