这个会是我策略的原因吗？还是bug.

File "c:\Users\yuanh\Documents\GitHub\vnpy\examples\add_by_yh\backtesting_yh.py", line 45, in <module>
engine.run_ga_optimization(setting)
 File "c:\Users\yuanh\Documents\GitHub\vnpy\vnpy\app\cta_strategy\backtesting.py", line 760, in run_gaoptimization
halloffame=hof
File "C:\vnstudio\Lib\site-packages\deap\algorithms.py", line 316, in eaMuPlusLambda
offspring = varOr(population, toolbox, lambda, cxpb, mutpb)
File "C:\vnstudio\Lib\site-packages\deap\algorithms.py", line 234, in varOr
ind1, ind2 = toolbox.mate(ind1, ind2)
File "C:\vnstudio\Lib\site-packages\deap\tools\crossover.py", line 51, in cxTwoPoint
cxpoint2 = random.randint(1, size - 1)
File "C:\vnstudio\Lib\random.py", line 222, in randint
return self.randrange(a, b+1)
File "C:\vnstudio\Lib\random.py", line 200, in randrange
raise ValueError("empty range for randrange() (%d,%d, %d)" % (istart, istop, width))
builtins.ValueError: empty range for randrange() (1,1, 0)
