SendFile protected?

Why TProof::SendFile is protected? How can I send a file to the workers? Suppose that during the TSelector::Process I need to read a data text file and I want to open and close it in TSelector::SlaveBegin, TSelector::SlaveTerminate. Suppose workers don’t share filesystem.

TProof::SendFile is used for internal purposes at session level.
See for ways to bring files to the sandbox.