content: package com.alibaba.fastjson2.issues_2200;
  
  import com.alibaba.fastjson2.*;
  import com.alibaba.fastjson2.util.ParameterizedTypeImpl;
  import org.junit.Assert;
  import org.junit.Test;
  
  import java.util.*;
  
  public class Issue2279 {
      @Test
      public void test01() {
          Map<Integer, List<Integer>> result = new HashMap<>();
          result.put(1, Arrays.asList(-1));
          result.put(2, Arrays.asList(-1));
  
          byte[] bytes = JSONB.toBytes(result, JSONWriter.Feature.WriteClassName, JSONWriter.Feature.FieldBased, JSONWriter.Feature.ErrorOnNoneSerializable, JSONWriter.Feature.ReferenceDetection, JSONWriter.Feature.WriteNulls, JSONWriter.Feature.NotWriteDefaultValue, JSONWriter.Feature.NotWriteHashMapArrayListClassName, JSONWriter.Feature.WriteNameAsSymbol);
          ParameterizedTypeImpl parameterizedType = new ParameterizedTypeImpl(Map.class, Integer.class, new ParameterizedTypeImpl(List.class, Integer.class));
          Map<Integer, List<Integer>> o = JSONB.parseObject(bytes, parameterizedType);
          Integer i = o.get(2).get(0);
          Assert.assertEquals(-1, (int) i);
      }
  }
  