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: basic.rs
    path of file: ./repos/hyperswitch/crates/masking/tests
    
    the code of the file until where you have to start completion: #![allow(dead_code, clippy::unwrap_used, clippy::panic_in_result_fn)]

use masking::Secret;
#[cfg(feature = "serde")]
use masking::SerializableSecret;
#[cfg(feature = "alloc")]
use masking::ZeroizableSecret;
#[cfg(feature = "serde")]
use serde::Serialize;

#[test]
fn basic() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    #[cfg_attr(feature = "serde
    
fn without_serialize() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    #[cfg_attr(feature = "serde", derive(Serialize))]
    #[derive(Clone, Debug, PartialEq, Eq)]
    pub struct AccountNumber(String);

    #[cfg(feature = "alloc")]
    impl ZeroizableSecret for AccountNumber {
        fn zeroize(&mut self) {
            self.0.zeroize();
        }
    }

    #[cfg_attr(feature = "serde", derive(Serialize))]
    #[derive(Clone, Debug, PartialEq, Eq)]
    pub struct Composite {
        #[cfg_attr(feature = "serde", serde(skip))]
        secret_number: Secret<AccountNumber>,
        not_secret: String,
    }

    // construct

    let secret_number = Secret::<AccountNumber>::new(AccountNumber("abc".to_string()));
    let not_secret = "not secret".to_string();
    let composite = Composite {
        secret_number,
        not_secret,
    };

    // format

    let got = format!("{composite:?}");
    let exp = r#"Composite { secret_number: *** basic::without_serialize::AccountNumber ***, not_secret: "not secret" }"#;
    assert_eq!(got, exp);

    // serialize

    #[cfg(feature = "serde")]
    {
        let got = serde_json::to_string(&composite).unwrap();
        let exp = r#"{"not_secret":"not secret"}"#;
        assert_eq!(got, exp);
    }

    // end

    Ok(())
}