/// <summary>
/// Send a post request with header value "User-Agent": "overwrite"
/// </summary>
/// <param name='operations'>
/// The operations group for this extension method.
/// </param>
/// <param name='userAgent'>
/// Send a post request with header value "User-Agent": "overwrite"
/// </param>
/// <param name='cancellationToken'>
/// The cancellation token.
/// </param>
public static async Task ParamExistingKeyAsync(this IHeader operations, string userAgent, CancellationToken cancellationToken = default(CancellationToken))
{
await operations.ParamExistingKeyWithHttpMessagesAsync(userAgent, null, cancellationToken).ConfigureAwait(false);
}
