public void test_raises_if_duplicate_normalized_keys_exist()
{
const string json = @"{ ""someKey"": ""value"", ""some_key"": ""value"" }";
var exception = Assert.Throws<InvalidOperationException>(() => new Config(json));
Assert.That(exception.Message, Is.StringContaining("duplicate"));
Assert.That(exception.Message, Is.StringContaining("someKey"));
Assert.That(exception.Message, Is.StringContaining("some_key"));
}