Russia bought Iranian drones for “Egyptian” Su-35s?

There has been unproven information that Iran has sent the first batch of drones to Russia for tests along with pilots who are expected to learn how to operate Russian Su-35 fighter jets, suggesting that Russia could hand over these aircraft to Iran, according to the American think tank Institute for the survey of War (ISW). It may be about Su-35 aircraft, previously manufactured for Egypt, which - according to earlier reports - yet abandoned the deal at U.S. pressure.