Get the number of generations of a TerminatorGenerations. When the TerminatorGenerations
is wrapped in a TerminatorCombo, then the minimum number of generations
allowed by it are retrieved. This is the minimum of all terminator_get_generations if $any is set
to TRUE, and the maximum if $any is set to FALSE.
The number of generations allowed by other Terminators is infinity.
terminator_get_generations(x)numeric(1): The theoretical maximum number of generations allowed by the Terminator.
(Terminator)
Terminator to query.