assert_eq!("tb", Currency::BitcoinTestnet.to_string());
assert_eq!("bcrt", Currency::Regtest.to_string());
assert_eq!("sb", Currency::Simnet.to_string());
assert_eq!("tb", Currency::BitcoinTestnet.to_string());
assert_eq!("bcrt", Currency::Regtest.to_string());
assert_eq!("sb", Currency::Simnet.to_string());