src/vs/editor/browser/viewParts/lineNumbers/lineNumbers.ts/LineNumbersOverlay/constructor
class LineNumbersOverlay:	constructor(context: ViewContext) {
		super();
		this._context = context;

		this._readConfig();

		this._lastCursorModelPosition = new Position(1, 1);
		this._renderResult = null;
		this._activeLineNumber = 1;
		this._context.addEventHandler(this);
	}