def assert_crypto_availability(f):
 @functools.wraps(f)
 def wrapper(*args, **kwds):
  if (AES is None):
   raise CryptoUnavailableError()
  return f(*args, **kwds)
 return wrapper

def assert_crypto_availability ( f ) : @ functools . wraps ( f ) def wrapper ( * args , ** kwds ) : if ( AES is None ) : raise CryptoUnavailableError ( ) return f ( * args , ** kwds ) return wrapper
ensure crypto module is available .