src/vs/base/common/async.ts/AsyncIterableObject/emitOne
class AsyncIterableObject:	private emitOne(value: T): void {
		if (this._state !== AsyncIterableSourceState.Initial) {
			return;
		}
		// it is important to add new values at the end,
		// as we may have iterators already running on the array
		this._results.push(value);
		this._onStateChanged.fire();
	}