src/vs/editor/contrib/hover/hoverOperation.ts/HoverOperation/_triggerAsyncComputation
class HoverOperation:	private _triggerAsyncComputation(): void {
		this._state = ComputeHoverOperationState.SECOND_WAIT;
		this._secondWaitScheduler.schedule(this._secondWaitTime());

		if (this._computer.computeAsync) {
			this._asyncComputationPromiseDone = false;
			this._asyncComputationPromise = createCancelablePromise(token => this._computer.computeAsync!(token));
			this._asyncComputationPromise.then((asyncResult: Result) => {
				this._asyncComputationPromiseDone = true;
				this._withAsyncResult(asyncResult);
			}, (e) => this._onError(e));

		} else {
			this._asyncComputationPromiseDone = true;
		}
	}