# : out example
# : dep cryptography
import sys
from typing import List

from cryptography.fernet import Fernet


def cryptic_hello(name: str) -> str:
    "Example taken from `cryptography` docs."
    key = Fernet.generate_key()
    f = Fernet(key)
    token = f.encrypt(hello(name).encode("utf-8"))
    ret = f.decrypt(token).decode("utf-8")
    assert ret == hello(name)
    return ret


def hello(name: str) -> str:
    return f"Hello {name}"


def main() -> None:
    if "test" in sys.argv:
        print("testing success")
    print(cryptic_hello("world"))


if __name__ == "__main__":
    main()