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: runtime_user.rs
    path of file: ./repos/nearcore/integration-tests/src/user
    
    the code of the file until where you have to start completion: use std::cell::RefCell;
use std::collections::{HashMap, HashSet};
use std::sync::{Arc, RwLock};

use near_chain_configs::MIN_GAS_PRICE;
use near_crypto::{PublicKey, Signer};
use near_jsonrpc_primitives::errors::ServerError;
use near_parameters::RuntimeConfig;
use near_primitives::errors::{RuntimeError, TxExecutionError};
use near_primitives::hash::Crypto
    
    fn view_contract_code(&self, account_id: &AccountId) -> Result<ContractCodeView, String> {
        let state_update = self.client.read().expect(POISONED_LOCK_ERR).get_state_update();
        self.trie_viewer
            .view_contract_code(&state_update, account_id)
            .map(|contract_code| {
                let hash = *contract_code.hash();
                ContractCodeView { hash, code: contract_code.into_code() }
            })
            .map_err(|err| err.to_string())
    }