public async Task<MethodResult> SetAvatarFromImageStreamAsync(Stream sourceStream, string mimeType)
{
var base64 = EncodingHelper.ConvertToBase64(sourceStream);
var end = $"data:{mimeType};base64,{base64}";
var results = await _client.CallAsync("setAvatarFromService", TimeoutToken, end, mimeType, "upload").ConfigureAwait(false);
return results.ToObject<MethodResult>(JsonSerializer);
}