code: public static Criterion between(String relativePath, Object lo, Object hi) {
      return new BetweenExpression(relativePath, lo, hi, false);
    }
docs: Adds a "between" constraint to a <i>persistent field</i>.
  
  @param relativePath relative path of the field
  @param lo the low end of the "between" expression
  @param hi the high end of the "between" expression
  @return {@link Criterion} instance