Airbus is testing a A321 (D-AVXA, flight AIB97XA) around Toulouse this morning. The test is at low altitude, with many speed and altitude changes, including touch and go (maybe rolling slowly on the runway):
This path crosses other commercial routes / VFR aircraft, and it seems unlikely altitude, speed or even position can be anticipated all the time, but could be determined only while in flight.
All these constraints surely mean a specific treatment from ATC. How does ATC control and coordinate this flight with other aircraft? Toulouse Blagnac (LFBO) is open to commercial flights, and this test flight was within or close to Toulouse TMA.