def ebchange(self, wlan):
        self.updatelock.acquire()
        if wlan not in self.updates:
            self.updates.append(wlan)
        self.updatelock.release()
Validates that a user exists with the given e-mail address.
dataset/ETHPy150Open coreemu/core/daemon/core/netns/vnet.py/EbtablesQueue.ebchange--crossover with--dataset/ETHPy150Open treeio/treeio/treeio/core/forms.py/PasswordResetForm.clean_username