code: public static <T extends Comparable<T>> RelationalOperator<T> lessThanEqualTo(T lowerBound) {
      return new LessThanEqualToOperator<>(lowerBound);
    }
docs: Gets the RelationalOperator performing less than equal to comparisons to determine whether all provided values
  are less than equal to the given upper bound value.
  
  @param lowerBound the Comparable upper bounded value.
  @param <T> the expected Class type for the object used in the less than equal to comparison.
  @return a RelationalOperator for the less than equal to comparison.