Duct rhsDuct;
if( group.isGroupBy() )
rhsDuct = new HadoopGroupByGate( flowProcess, (GroupBy) group, IORole.source );
else
rhsDuct = new HadoopCoGroupGate( flowProcess, (CoGroup) group, IORole.source );
addHead( rhsDuct );
handleDuct( group, rhsDuct );
}