class A:
    def __init__ (self):
        self.s = 'hello'
        
a = A ()

def run (autoTester):
    autoTester.check (a.s, getattr (a, 's'))
    
    setattr (a, 's', 'goodbye')
    autoTester.check (a.s, getattr (a, 's'))
    
    setattr (a, 't', 'exists')
    autoTester.check (hasattr (a, 't'), a.t, getattr (a, 't'))
    
    delattr (a, 't')
    autoTester.check (hasattr (a, 't'))
