/// <summary>
 /// Get null duration value
 /// </summary>
 /// <param name='operations'>
 /// The operations group for this extension method.
 /// </param>
 /// <param name='cancellationToken'>
 /// The cancellation token.
 /// </param>
 public static async Task <System.TimeSpan?> GetNullAsync(this IDuration operations, CancellationToken cancellationToken = default(CancellationToken))
 {
     using (var _result = await operations.GetNullWithHttpMessagesAsync(null, cancellationToken).ConfigureAwait(false))
     {
         return(_result.Body);
     }
 }
        /// <summary>
        /// Get null duration value
        /// </summary>
        /// <param name='operations'>
        /// The operations group for this extension method.
        /// </param>
        /// <param name='cancellationToken'>
        /// The cancellation token.
        /// </param>
        public static async Task <TimeSpan?> GetNullAsync(this IDuration operations, CancellationToken cancellationToken = default(CancellationToken))
        {
            HttpOperationResponse <TimeSpan?> result = await operations.GetNullWithHttpMessagesAsync(null, cancellationToken).ConfigureAwait(false);

            return(result.Body);
        }