Values.PullRequestCreatedEventMetadataSourceMetadata about the pull request that is used when comparing the pull request source with its destination.
type nonrec t = {repositoryName : RepositoryName.t option;The name of the repository where the pull request was created.
*)sourceCommitId : CommitId.t option;The commit ID on the source branch used when the pull request was created.
*)destinationCommitId : CommitId.t option;The commit ID of the tip of the branch specified as the destination branch when the pull request was created.
*)mergeBase : CommitId.t option;The commit ID of the most recent commit that the source branch and the destination branch have in common.
*)}