private static Func <string, string> GetComparerForWriterTestExpectedResults(BatchWriterUtils.ODataPayload odataPayload) { if (odataPayload.TestConfiguration.Format == ODataFormat.Atom) { return((observed) => { string error; if (!TestWriterUtils.CompareAtomResults( ((AtomWriterTestExpectedResults)odataPayload.WriterTestExpectedResults), observed, odataPayload.TestConfiguration, out error)) { return error; } return null; }); } if (odataPayload.TestConfiguration.Format == ODataFormat.Json) { return((observed) => { string error; if (!TestWriterUtils.CompareJsonResults( ((JsonWriterTestExpectedResults)odataPayload.WriterTestExpectedResults), observed, odataPayload.TestConfiguration, out error)) { return error; } return null; }); } throw new NotSupportedException("Only ATOM and JSON formats are supported for batch payloads."); }