code: @SuppressWarnings("unchecked")
      public void setProperty(Object obj, Object key, Object value) {
          if (isMap(obj))
              ((Map) obj).put(key.toString(), value);
          else {
              throw new JsonPathException("setProperty operation cannot be used with " + obj!=null?obj.getClass().getName():"null");
          }
      }
docs: Sets a value in an object
  
  @param obj   an object
  @param key   a String key
  @param value the value to set