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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 errored_tasks(self):
 """List of errored tasks."""

        etasks = []
        for status in [self.S_ERROR, self.S_QCRITICAL, self.S_ABICRITICAL]:
            etasks.extend(list(self.iflat_tasks(status=status)))

        return set(etasks)