System.IO.Compression.DeflateStream.CopyToAsync C# (CSharp) Method

        public override Task CopyToAsync(Stream destination, int bufferSize, CancellationToken cancellationToken)
        {
            // Validation as base CopyToAsync would do
            StreamHelpers.ValidateCopyToArgs(this, destination, bufferSize);

            // Validation as ReadAsync would do
            EnsureDecompressionMode();
            EnsureNoActiveAsyncOperation();
            EnsureNotDisposed();

            // Early check for cancellation
            if (cancellationToken.IsCancellationRequested)
            {
                return Task.FromCanceled<int>(cancellationToken);
            }

            // Do the copy
            return new CopyToAsyncStream(this, destination, bufferSize, cancellationToken).CopyFromSourceToDestination();
        }

 public override Task CopyToAsync(Stream destination, int bufferSize, CancellationToken cancellationToken)
 {
     CheckDeflateStream();
     return(_deflateStream.CopyToAsync(destination, bufferSize, cancellationToken));
 }