Turns this value into the desired type, if possible.
Correct implementations should delegate to super() after failing to cast, instead of returning None.
- desired_type – The type of thing that the caller wants to use.
- extensions – The extensions instance that is asking us to try to cast ourselves into something as part of its try_cast method. If we need to recursively cast some of our fields in order to cast ourselves, this is the extensions instance we should use.
- None if the receiving instance doesn’t recognize or can’t implement
the desired type. Otherwise a value that meets the interface.