private async Task <Stream> GetStreamAndWriteStartWrapperIfNecessaryAsync(XmlDictionaryWriter writer, object[] parameters, object returnValue)
{
Stream streamValue = GetStreamValue(parameters, returnValue);
if (streamValue == null)
{
throw DiagnosticUtility.ExceptionUtility.ThrowHelperArgumentNull(_partName);
}
if (WrapperName != null)
{
await writer.WriteStartElementAsync(null, WrapperName, WrapperNamespace);
}
await writer.WriteStartElementAsync(null, PartName, PartNamespace);
return(streamValue);
}
