code: public JSONWriter value(JSONString jss) throws JSONException {
          if (jss == null) {
              valueNull();
              return this;
          }
  
          try {
              String asString = jss.toJSONString();
              if (asString == null) {
                  throw new JSONException("Unexpected null from toJSONString");
              }
              appendValue(asString);
              return this;
          }
          catch (Exception e) {
              throw new JSONException(e);
          }
      }
docs: Append an object value derived from a custom JSONString implementation.
  This works identically to <code>value(Object o)</code> called on a
  on object whose actual type implements JSONString. This method is
  preferable because it by-passes the run-time type checking of the more
  general method.
  @param jss The JSONString object to append.
  It can be null or implement JSONString.
  @return this
  @throws JSONException if the value is out of sequence or if a
  toJSONString method throws an Exception or
  if the writer throws an IOException