Setting StopCriterion to ITERATIONS breaks the ElitismGPAlgorithm

[mitkonikov]

In the SymbolicRegressionExample.java file, changing the Task parameter for StopCriterion to StopCriterion.ITERATIONS breaks the ElitismGPAlgorithm even though properly the MaxIterations are set.

Setting the aforementioned line to:

Task<ProgramSolution, ProgramProblem> symbolicRegressionTask = new Task<>(sgpTrainingData, StopCriterion.ITERATIONS, 0, 0, 10000);

Results in the following error:

Exception in thread "main" java.lang.IllegalArgumentException: fromIndex(0) > toIndex(-100)
        at java.base/java.util.AbstractList.subListRangeCheck(AbstractList.java:509)
        at java.base/java.util.ArrayList.subList(ArrayList.java:1108)
        at org.um.feri.ears.algorithms.gp.ElitismGPAlgorithm.performEvaluation(ElitismGPAlgorithm.java:313)
        at org.um.feri.ears.algorithms.gp.ElitismGPAlgorithm.execute(ElitismGPAlgorithm.java:158)
        at org.um.feri.ears.algorithms.gp.ElitismGPAlgorithm.execute(ElitismGPAlgorithm.java:29)
        at org.um.feri.ears.examples.SymbolicRegressionExample.main(SymbolicRegressionExample.java:103)

If this is intended, it should return a proper throw message.