def METHOD_NAME():
    lib = Crypto()
    key = lib.generate_key()
    lib.use_encryption_key(key)
    text = "An example string\nWith some secret content"
    encrypted = lib.encrypt_string(text)
    assert encrypted != text
    assert base64.urlsafe_b64decode(encrypted) != text
    decrypted = lib.decrypt_string(encrypted)
    assert decrypted == text