readSequenceFile command should not reuse the identity of Hadoop Writeable objects

The readSequenceFile morphline command should not reuse the "key" and "value" Hadoop Writeable objects across rows.

Downstream commands such as loadSolr or HBase indexer buffer up a bunch of records before sending them off to Solr. If the buffered records contain a reference to the same Hadoop Writeable object as the primary key id, this leads to nonsensical behaviour as all the records suddently appear to be the same record (same id).

A work-around is to insert the commands

toString { field: key }
toString { field : value } 

immediately after the readSequenceFile command in your morphline. This converts the key and value from the Hadoop Writable to a distinct String object, which means the identity of the key and object are different for each row.