AddRadialForce and methods to debug code

[anonymous_user_4a05d675]

I found my mistake. I should have used AddRadialForce() in ABlackholeActor::Tick() method instead of ABlackholeActor::BeginPlay().

I tried using AddRadialImpulse(), too. Apparently, that on the other hand has to be used in ABlackholeActor::BeginPlay(). Otherwise, the impulse of the actors being pulled will keep increasing indefinitely.