The following code hangs forever instead of printing "called" 10 times:

    from concurrent.futures import ProcessPoolExecutor
    
    class A:
        def f(self):
            print("called")
    
    class B(A):
        def f(self):
            executor = ProcessPoolExecutor(max_workers=2)
            futures = [executor.submit(super(B, self).f)
                       for _ in range(10)]
    
    if __name__ == "__main__":
        B().f()

The same code with `super(B, self)` replaced with `super()` raises the following error:

> TypeError: super(type, obj): obj must be an instance or subtype of type

However, replacing `ProcessPoolExecutor` with `ThreadPoolExecutor` works  as expected, but only with `super(B, self)` (with `super()` it still raises the same error).