Implementing custom encoders is unfortunately not well supported at
the moment (IIRC there are plans to eventually add an api for user
defined encoders).
That being said, there are a couple of encoders that can work with
generic, serializable data types: "javaSerialization" and "kryo",
found here
e.g. I have a custom class A (not case class), and I'd like to use it as
DataSet[A]. I guess I need to implement Encoder for this, but didn't find
any example for that, is there any document for that ? Thanks
