UCMA 5.0 API for file transfer

How does Ucma5.0 supports file transfer in P-2-P chat. I could find code to accomplish that in Ucma4.0 something like:

ContentSharingModality contentSharingModality =        (ContentSharingModality)_conversation.Modalities[ModalityTypes.ContentSharing];        contentSharingModality.BeginCreateContentFromFile(ShareableContentType.NativeFile,        _NativeFileName, _NativeFileNameAndPath, true,        (ar) =>        {            ShareableContent sContent = contentSharingModality.EndCreateContentFromFile(ar);            _NativeFileNameAndPath = string.Empty;            sContent.Upload();            }        , null);        }

but could not find any substitute for the same in Ucma5.0.

I am trying to use

InstantMessagingFlow.BeginSendInstantMessage() function, which does not seem to support this.

Any pointers will be appreciated