src/vs/editor/contrib/suggest/browser/suggestController.ts/LineSuffix/constructor
class LineSuffix:	constructor(private readonly _model: ITextModel, private readonly _position: IPosition) {
		// spy on what's happening right of the cursor. two cases:
		// 1. end of line -> check that it's still end of line
		// 2. mid of line -> add a marker and compute the delta
		const maxColumn = _model.getLineMaxColumn(_position.lineNumber);
		if (maxColumn !== _position.column) {
			const offset = _model.getOffsetAt(_position);
			const end = _model.getPositionAt(offset + 1);
			this._marker = _model.deltaDecorations([], [{
				range: Range.fromPositions(_position, end),
				options: { description: 'suggest-line-suffix', stickiness: TrackedRangeStickiness.NeverGrowsWhenTypingAtEdges }
			}]);
		}
	}