private static TheoryData <EncryptionTestVector> RemovePartialByteTests(TheoryData <EncryptionTestVector> input) { IEnumerable <EncryptionTestVector> filteredTestVectors = input .Select(x => x[0]) .Cast <EncryptionTestVector>() .Where(x => x.DataUnitLength % 8 == 0); var output = new TheoryData <EncryptionTestVector>(); foreach (EncryptionTestVector item in filteredTestVectors) { output.Add(item); } return(output); }