src/vs/editor/browser/viewParts/lines/viewLine.ts/ViewLine/onMonospaceAssumptionsInvalidated
class ViewLine:	public onMonospaceAssumptionsInvalidated(): void {
		if (this._renderedViewLine && this._renderedViewLine instanceof FastRenderedViewLine) {
			this._renderedViewLine = this._renderedViewLine.toSlowRenderedLine();
		}
	}