Parsing object from retejs serialization format

Main.java

import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.ObjectMapper;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.Map;
import lombok.Data;

public class Main {

  public static void main(String[] args) throws IOException {
    var reader = new BufferedReader(new FileReader("./test.json"));
    StringBuilder b = new StringBuilder();
    String line;
    while ((line = reader.readLine()) != null) {
      b.append(line);
    }

    String json = b.toString();
    NodeGroup a = new ObjectMapper().readValue(json, new TypeReference<NodeGroup>() {
    });
    System.out.println("a");
  }

  @Data
  static class NodeGroup {

    private String id;
    private Map<String, Node> nodes;
  }

  @Data
  static class Node {

    private String id;
    private Map<String, Object> data;
    private String name;
    private Integer[] position;
    private Map<String, InputConnection> inputs;
    private Map<String, OutputConnection> outputs;
  }

  @Data
  static class InputConnection {

    private InputConnectionData[] connections;
  }

  @Data
  static class InputConnectionData {

    private Integer node;
    private String output;
    private Map<String, Object> data;
  }

  @Data
  static class OutputConnection {

    private OutputConnectionData[] connections;
  }

  @Data
  static class OutputConnectionData {

    private Integer node;
    private String input;
    private Map<String, Object> data;
  }

}