public void Encode_Map_With_Null_Value_Throws_ArgumentNullException() { var value = new Dictionary <string, string> { { "k1", "value1" }, { "k2", null } }; var ex = Assert.Throws <ArgumentNullException>(() => TypeCodec.EncodeMap(2, MapColumnInfoStringString, value)); StringAssert.Contains("collections", ex.Message); }