# Tricky initialization problem involving multiple inheritance.
# Uses super()

class Base:
    def __init__(self):
        print('Base.__init__')

class A(Base):
    def __init__(self):
        super().__init__()
        print('A.__init__')

class B(Base):
    def __init__(self):
        super().__init__()
        print('B.__init__')

class C(A,B):
    def __init__(self):
        super().__init__()     # Only one call to super() here
        print('C.__init__')

if __name__ == '__main__':
    # Observe that each class initialized only once
    c = C()