src/vs/editor/contrib/colorPicker/colorDetector.ts/ColorDetector/beginCompute
class ColorDetector:	private beginCompute(): void {
		this._computePromise = createCancelablePromise(token => {
			const model = this._editor.getModel();
			if (!model) {
				return Promise.resolve([]);
			}
			return getColors(model, token);
		});
		this._computePromise.then((colorInfos) => {
			this.updateDecorations(colorInfos);
			this.updateColorDecorators(colorInfos);
			this._computePromise = null;
		}, onUnexpectedError);
	}