[CASCADING] Provide the sink implementation
in order to write some parquet files with ParquetTupleScheme
NULL tuples cause NPE when writing
Merge pull request #1 from jalkjaer/cascading_sink

NULL tuples causes NPE when writing
Better writing of a loop
Merge pull request #285 from mickaellcr/cascading_sink

[CASCADING] Provide the sink implementation for ParquetTupleScheme