// =============================================================================
// Copyright (c) 2025 - 2026 Haixing Hu.
//
// SPDX-License-Identifier: Apache-2.0
//
// Licensed under the Apache License, Version 2.0.
// =============================================================================
//! Defines the duplicate-field fixture used by decoder tests.
use Deserialize;
/// Payload used to verify serde duplicate-field rejection.
pub