public Builder mergeFrom(Person other) {
        if (other == Person.getDefaultInstance()) return this;
        if (other.hasName()) {
          bitField0_ |= 0x00000001;
          name_ = other.name_;
          onChanged();
        }
        if (other.hasId()) {
          setId(other.getId());
        }
        if (other.hasEmail()) {
          bitField0_ |= 0x00000004;
          email_ = other.email_;
          onChanged();
        }
        this.mergeUnknownFields(other.getUnknownFields());
        onChanged();
        return this;
      }
Protobuf type {@code com.alibaba.fastjson2.protobuf.Person}
core/src/test/java/com/alibaba/fastjson2/protobuf/PersonOuterClass.java