如何仅序列化变量的名称并忽略struct (serde)中枚举字段的值

use serde::{Serialize, Serializer, Deserialize, Deserializer};

#[derive(Serialize, Deserialize)]
struct MyStruct {
    #[serde(serialize_with = "serialize_field")]
    field1: String,
    field2: u32,
    field3: MyEnum,
}

#[derive(Serialize, Deserialize)]
enum MyEnum {
    #[serde(rename = "enum1")]
    Enum1,
    #[serde(rename = "enum2")]
    Enum2,
}

fn serialize_field<S>(field: &String, serializer: S) -> Result<S::Ok, S::Error>
where
    S: Serializer,
{
    serializer.serialize_str(field)
}

fn main() {
    let my_struct = MyStruct {
        field1: "value1".to_string(),
        field2: 42,
        field3: MyEnum::Enum1,
    };

    let serialized = serde_json::to_string(&my_struct).unwrap();
    println!("Serialized: {}", serialized);
}

Serialized: {"field1":"field1","field2":42,"field3":"enum1"}