code: public static String ensureRight(final String value, final String suffix, boolean caseSensitive) {
          validate(value, NULL_STRING_PREDICATE, NULL_STRING_MSG_SUPPLIER);
          return endsWith(value, suffix, caseSensitive) ? value : append(value, suffix);
      }
docs: Ensures that the value ends with suffix. If it doesn't, it's appended.
  
  @param value         The input String
  @param suffix        The substr to be ensured to be right
  @param caseSensitive Use case (in-)sensitive matching for determining if value already ends with suffix
  @return The string which is guarenteed to start with substr