SpaDES.callingModuleName returns the name of the module that is currently
the active module calling functions like scheduleEvent.
This will only return the module name if it is inside a spades call,
i.e., it will return NULL if used in interactive mode.
The related function currentModule is simply a rapid accessor for the
current module name. This latter will return the module that is in the current
event queue, which will never be NULL.
.callingModuleName(sim)# S4 method for simList
.callingModuleName(sim)
currentModule(sim)
# S4 method for simList
currentModule(sim)
.callingFrameTimeunit(x)
A simList object from which to extract element(s) or
in which to replace element(s).
A simList