code: function LineNumberCompareRuler (diffNavigator, mapperColumnIndex , annoModel, rulerLocation, rulerStyle, oddStyle, evenStyle) {
  		orion.CompareRuler.call(this, annoModel, rulerLocation, "page", rulerStyle); //$NON-NLS-0$
  		this._diffNavigator = diffNavigator;
  		this._oddStyle = oddStyle || {style: {backgroundColor: "white"}}; //$NON-NLS-0$
  		this._evenStyle = evenStyle || {style: {backgroundColor: "white"}}; //$NON-NLS-0$
  		this._numOfDigits = 0;
  		this._mapperColumnIndex = mapperColumnIndex;
  	}
docs: Creates a new line number ruler for the compare editor.
  @class The line number ruler is used by the compare editor to render line numbers next to the editor
  @name orion.compare.rulers.LineNumberCompareRuler