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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def customers(self):
        '''
        List both any individuals signed up via the registration and payment system,
        and any individuals signed up without payment.
        '''
        return Customer.objects.filter(
            Q(privatelessoncustomer__lesson=self) |
            Q(registration__eventregistration__event=self)
        ).distinct()