src/vs/workbench/api/common/extHostLanguageFeatures.ts/InlayHintsAdapter/provideInlayHints
class InlayHintsAdapter:	provideInlayHints(resource: URI, range: IRange, token: CancellationToken): Promise<extHostProtocol.IInlayHintsDto | undefined> {
		const doc = this._documents.getDocument(resource);
		return asPromise(() => this._provider.provideInlayHints(doc, typeConvert.Range.to(range), token)).then(value => {
			return value ? { hints: value.map(typeConvert.InlayHint.from) } : undefined;
		});
	}