Working with DataStreams of Java objects in Pyflink?

[Kevin Lam]

Hi all,

Looking to use Pyflink to work with some scala-defined objects being
emitted from a custom source. When trying to manipulate the objects in a
pyflink defined MapFunction
<https://ci.apache.org/projects/flink/flink-docs-release-1.12/api/python/pyflink.datastream.html#pyflink.datastream.MapFunction>,
I'm hitting an error like:

Caused by: java.lang.UnsupportedOperationException: The type information:
Option[<...>$Record(id: Long, created_at: Option[Long], updated_at:
Option[Long])] is not supported in PyFlink currently.

The scala object is defined something like:

```
object <...> {
  case class Record(
    id: Long,
    created_at: Option[Long],
    updated_at: Option[Long],
    ...
  )
}
```

The pyflink code is something like:

```
class Mutate(MapFunction):
  def map(self,value):
    print(value.id)
    value.id = 123

...

records = env.add_source(..)
records = records.map(Mutate()
```

Can you provide any advice on how to work with these kinds of objects in
Pyflink?

Thanks in advance!