fix the bug of 'Patient does not exist', modify the hashcode of the preexisting patient
fix the bug of 'Patient does not exist', modify the hashcode of the preexisting patient

ScreenBasedSimulator/ScreenBasedSimulator2,ScreenBasedSimulator/ScreenBasedSimulator2,ScreenBasedSimulator/ScreenBasedSimulator2,ScreenBasedSimulator/ScreenBasedSimulator2