src/vs/editor/common/viewLayout/lineDecorations.ts/LineDecoration/_equals
class LineDecoration:	private static _equals(a: LineDecoration, b: LineDecoration): boolean {
		return (
			a.startColumn === b.startColumn
			&& a.endColumn === b.endColumn
			&& a.className === b.className
			&& a.type === b.type
		);
	}