src/vs/base/browser/fastDomNode.ts/FastDomNode/setLetterSpacing
class FastDomNode:	public setLetterSpacing(letterSpacing: number): void {
		if (this._letterSpacing === letterSpacing) {
			return;
		}
		this._letterSpacing = letterSpacing;
		this.domNode.style.letterSpacing = this._letterSpacing + 'px';
	}