如何在Rust的‘Aes`机箱中设置初始化向量(IV)？(AES-128 CBC)

[dependencies]
rust-crypto = "0.2"

extern crate crypto;

use crypto::symmetriccipher::blockcipher::{BlockCipher, NewBlockCipher};
use crypto::symmetriccipher::generic_array::GenericArray;
use crypto::symmetriccipher::encryptor::{Encryptor, EncryptorX8};
use crypto::blockmodes::CbcEncryptor;
use crypto::buffer::{RefReadBuffer, RefWriteBuffer};
use crypto::aes::{Aes128, KeySize};
use crypto::aessafe::AesSafe128Encryptor;
use crypto::rand::Rng;

let mut key: [u8; 16] = [0; 16];
let mut iv: [u8; 16] = [0; 16];

// 生成随机的密钥
let mut rng = rand::thread_rng();
rng.fill_bytes(&mut key);

// 生成随机的初始化向量
rng.fill_bytes(&mut iv);

let key = GenericArray::from_slice(&key);
let iv = GenericArray::from_slice(&iv);

let encryptor = AesSafe128Encryptor::new(&key, &iv);
let encryptor = CbcEncryptor::new(encryptor);

let mut ciphertext = [0u8; 16];
let mut read_buffer = RefReadBuffer::new(&plaintext);
let mut write_buffer = RefWriteBuffer::new(&mut ciphertext);

encryptor.encrypt(&mut read_buffer, &mut write_buffer, true).unwrap();