code: private JSONValue toJsonStringList(Collection<? extends Object> list) {
  
          if (null != list) {
              JSONArray array = new JSONArray();
              for (Object o : list) {
                  array.set(array.size(), new JSONString(o.toString()));
              }
              return array;
          } else {
              return null;
          }
      }
docs: Convert a list of objects to a JSON array with the string representations of that objects.
  @param list the list of objects.
  @return the JSON array with the string representations.