private Set<StoragePort> andNotStoragePorts(Set<StoragePort> a,Set<String> b){
  Set<StoragePort> result=new HashSet<StoragePort>();
  for (  StoragePort port : a) {
    if (!b.contains(port.getPortNetworkId())) {
      result.add(port);
    }
  }
  return result;
}

private Set < StoragePort > andNotStoragePorts ( Set < StoragePort > a , Set < String > b ) { Set < StoragePort > result = new HashSet < StoragePort > ( ) ; for ( StoragePort port : a ) { if ( ! b . contains ( port . getPortNetworkId ( ) ) ) { result . add ( port ) ; } } return result ; }
returns a and ( not b )
