Function encrypt 

pub fn encrypt<R, B, S>(
    rng: &mut R,
    pk: B,
    password: S,
    address: Option<String>,
    label: Option<String>,
) -> Result<KeyStore, KeyStoreError>
where
    R: Rng + CryptoRng,
    B: AsRef<[u8]>,
    S: AsRef<[u8]>,

Encrypts the given private key using the Scrypt password-based key derivation function.

Example

use web3_keystore::{encrypt, decrypt};
use rand::Rng;
let mut rng = rand::thread_rng();
let secret: [u8; 32] = rng.gen();
let password = "super-secret-password";
let address = Some(String::from("0x0"));
let keystore = encrypt(
    &mut rng, &secret, password, address, None).unwrap();
let private_key = decrypt(&keystore, password).unwrap();
assert_eq!(secret.to_vec(), private_key);