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: lib.rs
    path of file: ./repos/ink/integration-tests/flipper
    
    the code of the file until where you have to start completion: #![cfg_attr(not(feature = "std"), no_std, no_main)]

#[ink::contract]
pub mod flipper {
    #[ink(storage)]
    pub struct Flipper {
        value: bool,
    }

    impl Flipper {
        /// Creates a new flipper smart contract initialized with the given value.
        #[ink(constructor)]
        pu
    
        async fn it_works<Client: E2EBackend>(mut client: Client) -> E2EResult<()> {
            // given
            let mut constructor = FlipperRef::new(false);
            let contract = client
                .instantiate("flipper", &ink_e2e::alice(), &mut constructor)
                .submit()
                .await
                .expect("instantiate failed");
            let mut call_builder = contract.call_builder::<Flipper>();

            let get = call_builder.get();
            let get_res = client.call(&ink_e2e::bob(), &get).dry_run().await?;
            assert!(matches!(get_res.return_value(), false));

            // when
            let flip = call_builder.flip();
            let _flip_res = client
                .call(&ink_e2e::bob(), &flip)
                .submit()
                .await
                .expect("flip failed");

            // then
            let get = call_builder.get();
            let get_res = client.call(&ink_e2e::bob(), &get).dry_run().await?;
            assert!(matches!(get_res.return_value(), true));

            Ok(())
        }