TdApi: set custom name for a file before downloading

Question

I have an application that downloads photos from messages (with TdApi.DownloadFile), and I want to set custom names for the files. I thought that it is impossible until I found ignoreFileNames parameter in TDLibSettings (it changes filenames to "file_0.jpg", "file_1.jpg", etc). If TDLib can manage file names, maybe it is possible to do this manually...

I tried to set file.local.path, but as expected it doesn't work.

Thanks for your help