question: private void updateBlockMirrorConsistencyGroup ( ) { log . info ( "Migrating BlockMirror consistencyGroup to consistencyGroups." ) ; DbClient dbClient = getDbClient ( ) ; List < URI > blockMirrorURIs = dbClient . queryByType ( BlockMirror . class , false ) ; Iterator < BlockMirror > blockMirrors = dbClient . queryIterativeObjects ( BlockMirror . class , blockMirrorURIs ) ; List < BlockObject > blockObjects = new ArrayList < BlockObject > ( ) ; while ( blockMirrors . hasNext ( ) ) { blockObjects . add ( blockMirrors . next ( ) ) ; } migrate ( blockObjects ) ; }
target:  Update the BlockMirror object to migrate the old consistencyGroup field into the new consistencyGroup list field.