code: public Invocation readInvocation(InputStream in) throws ConversionException, IOException, ClassNotFoundException {
          JSONObject json = parseObject(in);
          Invocation ret = new Invocation();
          ret.params = readPOJOArray(json.get(N_PARAMS));
          ret.signature = readStringArrayInternal(json.get(N_SIGNATURE));
          return ret;
      }
docs: Decode a JSON document to retrieve an Invocation instance.
  
  @param in The stream to read JSON from
  @return The decoded Invocation instance
  @throws ConversionException If JSON uses unexpected structure/format
  @throws IOException If an I/O error occurs or if JSON is ill-formed.
  @throws ClassNotFoundException If needed class can't be found.
  @see #writeInvocation(OutputStream, Invocation)