def METHOD_NAME(ctx):
    """sets ctx.data to a ed25519 private key"""
    key = ed25519.Ed25519PrivateKey.generate()
    ctx.data = str(
        key.private_bytes(
            encoding=serialization.Encoding.PEM,
            format=serialization.PrivateFormat.PKCS8,
            encryption_algorithm=serialization.NoEncryption(),
        ),
        "utf-8",
    )