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: env.rs
    path of file: ./repos/ink/crates/ink/codegen/src/generator
    
    the code of the file until where you have to start completion: // Copyright (C) Parity Technologies (UK) Ltd.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or i
    
    fn generate_code(&self) -> TokenStream2 {
        let env = self.contract.config().env();
        let storage_ident = self.contract.module().storage().ident();
        quote! {
            impl ::ink::env::ContractEnv for #storage_ident {
                type Env = #env;
            }

            type Environment = <#storage_ident as ::ink::env::ContractEnv>::Env;

            type AccountId = <<#storage_ident as ::ink::env::ContractEnv>::Env as ::ink::env::Environment>::AccountId;
            type Balance = <<#storage_ident as ::ink::env::ContractEnv>::Env as ::ink::env::Environment>::Balance;
            type Hash = <<#storage_ident as ::ink::env::ContractEnv>::Env as ::ink::env::Environment>::Hash;
            type Timestamp = <<#storage_ident as ::ink::env::ContractEnv>::Env as ::ink::env::Environment>::Timestamp;
            type BlockNumber = <<#storage_ident as ::ink::env::ContractEnv>::Env as ::ink::env::Environment>::BlockNumber;
            type ChainExtension = <<#storage_ident as ::ink::env::ContractEnv>::Env as ::ink::env::Environment>::ChainExtension;
            const MAX_EVENT_TOPICS: usize = <<#storage_ident as ::ink::env::ContractEnv>::Env as ::ink::env::Environment>::MAX_EVENT_TOPICS;
        }
    }