src/vs/editor/browser/services/abstractCodeEditorService.ts/DecorationCSSRules/getCSSTextForModelDecorationClassName
class DecorationCSSRules:	private getCSSTextForModelDecorationClassName(opts: IThemeDecorationRenderOptions | undefined): string {
		if (!opts) {
			return '';
		}
		const cssTextArr: string[] = [];
		this.collectCSSText(opts, ['backgroundColor'], cssTextArr);
		this.collectCSSText(opts, ['outline', 'outlineColor', 'outlineStyle', 'outlineWidth'], cssTextArr);
		this.collectBorderSettingsCSSText(opts, cssTextArr);
		return cssTextArr.join('');
	}