code: public static <S> List<S> selectNRandomDifferentSolutions(
        int numberOfSolutionsToBeReturned, List<S> solutionList) {
      JMetalRandom random = JMetalRandom.getInstance();
      return selectNRandomDifferentSolutions(numberOfSolutionsToBeReturned, solutionList, (low, up) -> random.nextInt(low, up));
    }
docs: This method receives a normalized list of non-dominated solutions and return the inverted one.
  This operation is needed for minimization problem
  
  @param solutionList The front to invert
  @return The inverted front