src/vs/workbench/api/common/extHostTypes.ts/DiagnosticRelatedInformation/isEqual
class DiagnosticRelatedInformation:	static isEqual(a: DiagnosticRelatedInformation, b: DiagnosticRelatedInformation): boolean {
		if (a === b) {
			return true;
		}
		if (!a || !b) {
			return false;
		}
		return a.message === b.message
			&& a.location.range.isEqual(b.location.range)
			&& a.location.uri.toString() === b.location.uri.toString();
	}