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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def generate_key( ctx, slot, public_key_output, management_key, pin, algorithm, format, pin_policy, touch_policy):
 """ Generate an asymmetric key pair. The private key is generated on the YubiKey, and written to one of the slots. \b SLOT PIV slot where private key should be stored. PUBLIC-KEY File containing the generated public key. Use '-' to use stdout. """


    dev = ctx.obj['dev']
    controller = ctx.obj['controller']

    _ensure_authenticated(ctx, controller, pin, management_key)

    algorithm_id = ALGO.from_string(algorithm)

    if pin_policy:
        pin_policy = PIN_POLICY.from_string(pin_policy)
    if touch_policy:
        touch_policy = TOUCH_POLICY.from_string(touch_policy)

    _check_pin_policy(ctx, dev, controller, pin_policy)
    _check_touch_policy(ctx, controller, touch_policy)

    try:
        public_key = controller.generate_key(
            slot,
            algorithm_id,
            pin_policy,
            touch_policy)
    except UnsupportedAlgorithm:
        ctx.fail('Algorithm {} is not supported by this '
                 'YubiKey.'.format(algorithm))

    key_encoding = format
    public_key_output.write(public_key.public_bytes(
            encoding=key_encoding,
            format=serialization.PublicFormat.SubjectPublicKeyInfo))