Version control systems The specified class must subclass VersionControlSystem. Commit dialog extensions. The specified class must subclass CommitDialogExtension. Commands to be shown in the context menu of the status view. The id must match an existing code. The provided type must be a subclass of VersionControlCommandHandler. Context menu for the blame view. Handler used to create the a diff view which can display the current file. Handler used to create the a blame view which can display the current file. Handler used to create the a log view which can display the current file. Handler used to create the a merge view which can display the current file. Context menu for the diff view.