You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: common.rs
    path of file: ./repos/aquatic/crates/ws_protocol/src
    
    the code of the file until where you have to start completion: use serde::{de::Visitor, Deserialize, Deserializer, Serialize, Serializer};

#[derive(Debug, Clone, Copy, Hash, PartialEq, Eq, Serialize, Deserialize)]
#[serde(transparent)]
pub struct PeerId(
    #[serde(
        deserialize_with = "deserialize_20_bytes",
        serialize_wi
    
    fn test_serde_20_bytes() {
        let info_hash = info_hash_from_bytes(b"aaaabbbbccccddddeeee");

        let info_hash_2 = unsafe {
            let mut out = ::simd_json::serde::to_string(&info_hash).unwrap();

            ::simd_json::serde::from_str(&mut out).unwrap()
        };

        assert_eq!(info_hash, info_hash_2);
    }