public void Should_validate_document_key_fields()
{
var doc1 = new Dictionary<string, object>()
.String("key1", "123")
.String("key2", "a123-4:5_6")
.String("key3", "1.23")
.Long("key4", 123)
.Object("key5", null)
.String("key6", "");
Assert.IsTrue(doc1.IsKey("key1"));
Assert.IsTrue(doc1.IsKey("key2"));
Assert.IsFalse(doc1.IsKey("key3"));
Assert.IsFalse(doc1.IsKey("key4"));
Assert.IsFalse(doc1.IsKey("key5"));
Assert.IsFalse(doc1.IsKey("key6"));
Assert.IsFalse(doc1.IsKey("nonExistingField"));
}