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: in_memory_db.rs
    path of file: ./repos/foundry/crates/evm/core/src/backend
    
    the code of the file until where you have to start completion: //! The in memory DB
use crate::{backend::error::DatabaseError, snapshot::Snapshots};
use alloy_primi
    
    fn cache_db_insert_basic_non_existing() {
        let mut db = CacheDB::new(EmptyDB::default());
        let address = Address::random();
        // call `basic` on a non-existing account
        let info = Database::basic(&mut db, address).unwrap();
        assert!(info.is_none());
        let mut info = info.unwrap_or_default();
        info.balance = U256::from(500u64);

        // insert the modified account info
        db.insert_account_info(address, info);

        // when fetching again, the `AccountInfo` is still `None` because the state of the account
        // is `AccountState::NotExisting`, see <https://github.com/bluealloy/revm/blob/8f4348dc93022cffb3730d9db5d3ab1aad77676a/crates/revm/src/db/in_memory_db.rs#L217-L226>
        let info = Database::basic(&mut db, address).unwrap();
        assert!(info.is_none());
    }