nl.markv:result (maven): `Result` is a value that can be either `Ok` or `Err`, to signal whether an operation succeeded or failed. Each variant can contain data, e.g. `Result<User, ErrMsg>` contains a `User` if ok, and `ErrMsg` when it fails. 
Keywords: algebraic-data-types|error-handling|java|jvm|result|sealed-class|types