src/vs/workbench/api/browser/mainThreadLanguageFeatures.ts/MainThreadLanguageFeatures/$registerRangeFormattingSupport
class MainThreadLanguageFeatures:	$registerRangeFormattingSupport(handle: number, selector: IDocumentFilterDto[], extensionId: ExtensionIdentifier, displayName: string): void {
		this._registrations.set(handle, modes.DocumentRangeFormattingEditProviderRegistry.register(selector, <modes.DocumentRangeFormattingEditProvider>{
			extensionId,
			displayName,
			provideDocumentRangeFormattingEdits: (model: ITextModel, range: EditorRange, options: modes.FormattingOptions, token: CancellationToken): Promise<ISingleEditOperation[] | undefined> => {
				return this._proxy.$provideDocumentRangeFormattingEdits(handle, model.uri, range, options, token);
			}
		}));
	}