src/vs/workbench/api/browser/mainThreadSaveParticipant.ts/SaveParticipant/constructor
class SaveParticipant:	constructor(
		extHostContext: IExtHostContext,
		@IInstantiationService instantiationService: IInstantiationService,
		@ITextFileService private readonly _textFileService: ITextFileService
	) {
		this._saveParticipantDisposable = this._textFileService.files.addSaveParticipant(instantiationService.createInstance(ExtHostSaveParticipant, extHostContext));
	}