expectation from PigStorage.getInputFormat() is that it is a
InputFormat<Writable, Text>, and PigStorage handles converting Text to
This is very useful and easy for users to use some other input format.
But the same is not true for PigStorage().getOutputFormat().. Here it
expects OutputFormat<Writable, Tuple>. So the output format needs to convert
Tuple to Text().
Not sure if this is intentional or not. I can submit a patch to move Tuple
handling into PigStorage. Then PigTextOutputFormat would be as thin as