src/vs/workbench/api/common/extHostTypes.ts/DiagnosticRelatedInformation/is
class DiagnosticRelatedInformation:	static is(thing: any): thing is DiagnosticRelatedInformation {
		if (!thing) {
			return false;
		}
		return typeof (<DiagnosticRelatedInformation>thing).message === 'string'
			&& (<DiagnosticRelatedInformation>thing).location
			&& Range.isRange((<DiagnosticRelatedInformation>thing).location.range)
			&& URI.isUri((<DiagnosticRelatedInformation>thing).location.uri);
	}