content: package com.alibaba.json.bvt;
  
  import junit.framework.Assert;
  import junit.framework.TestCase;
  
  import com.alibaba.fastjson.JSON;
  import com.alibaba.fastjson.annotation.JSONField;
  import com.alibaba.fastjson.serializer.SerializeConfig;
  import com.alibaba.fastjson.serializer.SerializerFeature;
  
  public class FeaturesTest extends TestCase {
  
      public void test_0() throws Exception {
          SerializeConfig config = new SerializeConfig();
          config.setAsmEnable(false);
          
          String text = JSON.toJSONString(new Entity(), config);
          Assert.assertEquals("{\"value\":null}", text);
      }
      
      public void test_1() throws Exception {
          SerializeConfig config = new SerializeConfig();
          config.setAsmEnable(true);
          
          String text = JSON.toJSONString(new Entity(), config);
          Assert.assertEquals("{\"value\":null}", text);
      }
  
      public static class Entity {
  
          private Object value;
  
          @JSONField(serialzeFeatures = { SerializerFeature.WriteMapNullValue })
          public Object getValue() {
              return value;
          }
  
          public void setValue(Object value) {
              this.value = value;
          }
  
      }
  }
  