How about adding validation to MongoCustomConversions class constructor

[hqsz]

First, thank you for supporting spring framework.

I encounter this converter issue while i developing with spring & mongodb. Also, we have solution to avoid above issue, but there seems to be a hole that can create problems(unexpected behavior to service developers)

So, how about validation (at least add warning) to Converter<String, Enum> without ReadingConverter annotation? If it is okay, can i try on this issue? 😄

Please review positively! have a nice day