@Override
            protected Input begin(Pipe.Schema<?> pipeSchema) throws IOException
            {
                if (parser.nextToken() != JsonToken.START_OBJECT)
                {
                    throw new JsonInputException("Expected token: { but was " +
                            parser.getCurrentToken() + " on message " +
                            pipeSchema.wrappedSchema.messageFullName());
                }

                return jsonInput;
            }
Creates a json pipe from a {@link JsonParser}.
protostuff-json/src/main/java/io/protostuff/JsonIOUtil.java