Presently, the IncidentSelector can be of two different kinds:
nullOnlySelector:Works with VSimPD and VSimPA licenses.
To be used if the MonteCarloInteractions` block contains only Null Interaction blocks, each interaction is performed consecutively at each time step. If any Interaction blocks are present, they are ignored.
unbiasedSelectorWorks with VSimPD and VSimPA licenses.
Selects incidents in an unbiased manner according to their probability only. This selector allows each macroparticle to interact only once per time step.