code: private int findAvailablePortNumber( Integer portNumberStartingPoint, List<Integer> reservedPorts )
      {
          assert portNumberStartingPoint != null;
          int candidate = portNumberStartingPoint;
          while ( reservedPorts.contains( candidate ) )
          {
              candidate++;
          }
          return candidate;
      }
docs: Returns the first number available, starting at portNumberStartingPoint that's not already in the reservedPorts
  list.
  
  @param portNumberStartingPoint first port number to start from.
  @param reservedPorts the ports already reserved.
  @return first number available not in the given list, starting at the given parameter.