private async Task<Stream> GetContent(HttpResponseMessage message, object state = null)
{
    if (message == null)
    {
        throw new ArgumentNullException(nameof(message));
    }

    using (HttpContent content = message.Content)
    {
        Stream contentStream = await content.ReadAsStreamAsync();
        if (contentStream == null)
        {
            throw new InvalidOperationException("The content stream is null.");
        }

        IEnumerable<string> encoding;
        if (message.Headers.TryGetValues("Content-Encoding", out encoding))
        {
            List<string> encodingList = encoding.ToList();

            if (encodingList.FirstOrDefault() != null)
            {
                bool compressed = encodingList.First().Equals("gzip", StringComparison.OrdinalIgnoreCase);
                if (compressed)
                {
                    Stream uncompressed = this.gzipInflator.Convert(contentStream, state);
                    if (uncompressed != null)
                    {
                        contentStream = uncompressed;
                    }
                    else
                    {
                        throw new InvalidOperationException("Could not read stream.");
                    }
                }
            }
        }

        await contentStream.FlushAsync();
        contentStream.Position = 0;
        return contentStream;
    }
}

public async Task<TOutput> ConvertElementAsync<TInput, TOutput>(HttpResponseMessage responseMessage, IConverter<TInput, TOutput> innerConverter, CancellationToken cancellationToken, object state = null)
{
    var contentStream = await this.GetContent(responseMessage, state);

    TInput response = this.serializerFactory.GetSerializer<TInput>().Deserialize(contentStream);

    return innerConverter.Convert(response, state);
}

public async Task<TOutput> ConvertElementAsync<TInput, TOutput>(HttpResponseMessage responseMessage, IConverter<TInput, TOutput> innerConverter, CancellationToken cancellationToken, object state = null)
{
    if (responseMessage == null)
    {
        throw new ArgumentNullException(nameof(responseMessage));
    }

    using (HttpContent content = responseMessage.Content)
    {
        Stream contentStream = await content.CopyToAsync();
        if (contentStream == null)
        {
            throw new InvalidOperationException("The content stream is null.");
        }

        IEnumerable<string> encoding;
        if (responseMessage.Headers.TryGetValues("Content-Encoding", out encoding))
        {
            List<string> encodingList = encoding.ToList();

            if (encodingList.FirstOrDefault() != null)
            {
                bool compressed = encodingList.First().Equals("gzip", StringComparison.OrdinalIgnoreCase);
                if (compressed)
                {
                    Stream uncompressed = this.gzipInflator.Convert(contentStream, state);
                    if (uncompressed != null)
                    {
                        contentStream = uncompressed;
                    }
                    else
                    {
                        throw new InvalidOperationException("Could not read stream.");
                    }
                }
            }
        }

    }

    TInput response = this.serializerFactory.GetSerializer<TInput>().Deserialize(contentStream);

    return innerConverter.Convert(response, state);
}