Scala Tuple2 not recognized as a Scala Tuple

[Pieter-Jan Van Aeken]

>From the Java API, I get an instance of_ DataSet_​ which I wrap with
the method available in _org.apache.flink.api.scala.package. _This
works fine when I print out the result, but when I try to write as
CSV, I get an exception:

java.lang.IllegalArgumentException: requirement failed: CSV output can
only be used with Tuple DataSets.

It seems that an instance of _DataSet[scala.Tuple2[Long, Long]]_ is
somehow considered different from an instance of_ DataSet[(Long,
Long)]_

Are there any suggestions on how to fix this problem? Note that I
cannot hardcode the conversion as the tuple size may vary or it might
be an entirely different custom class.

Regards,

Pieter-Jan