Most of the examiners I fly with as a candidate close a mixture control during the take-off roll - but, as said above, there's nothing to say this exercise is as a result of engine failure - it could be dog running across the runway, runway incursion, door opening, annunciator light coming on, tower controller yelling "stop, stop, stop"...anything.
When I do the same exercise (to comply with the test profile) I just brief that I will say "Abort" (which I do at nominated Vr minus 15 knots). Close the throttles and stop or vacate.
I still say C Y B's fountain of all knowledge is speaking from personal choice or company ops manual - not any "mandate" from outside sources (and, if so, shouldn't really dictate it as law to those who look up to him/her/it).