code: public static <T> ExpressionList<T> betweenIfNotNull(ExpressionList<T> expressionList,
                                                           String propertyName,
                                                           Object start,
                                                           Object end) {
          Assert.notNull(expressionList, "expressionList must not null");
          Assert.hasText(propertyName, "propertyName must not null");
          if (start != null && end != null) {
              return expressionList.between(propertyName, start, end);
          }
          return expressionList;
      }
docs: Return a ExpressionList specifying propertyName between start and end.
  
  @param expressionList the ExpressionList to add contains expression
  @param propertyName   the property name of entity bean.
  @param start          start value.
  @param end            end value.
  @param <T>            the type of entity.
  @return a ExpressionList specifying propertyName between start and end.