question: public void addToEquivalentMasks ( ExportMask exportMask , ExportMaskPolicy policy ) { String key = generatePolicyKey ( policy ) ; Set < URI > similarMasks = equivalentMasks . get ( key ) ; if ( similarMasks == null ) { similarMasks = new HashSet < > ( ) ; equivalentMasks . put ( key , similarMasks ) ; } similarMasks . add ( exportMask . getId ( ) ) ; exportMaskPolicy . put ( exportMask . getId ( ) , policy ) ; }
target:  Groups ExportMask based on ExportMaskPolicy equivalence (minus the #volumes)