CustomerEmailUnique example

                    'languageId' => Defaults::LANGUAGE_SYSTEM,
                    'currencyId' => Defaults::CURRENCY,
                    'snippetSetId' => $this->getSnippetSetIdForLocale('en-GB'),
                    'url' => 'http://localhost2',
                ],
            ],
        ];

        $salesChannelContext2 = $this->createSalesChannelContext($salesChannelParameters);

        $constraint = new CustomerEmailUnique([
            'context' => $salesChannelContext2->getContext(),
            'salesChannelContext' => $salesChannelContext2,
        ]);

        $validation = new DataValidationDefinition('customer.email.update');
        $validation->add('email', $constraint);

        $validator = $this->getContainer()->get(DataValidator::class);
        $validator->validate(['email' => $email], $validation);
    }

    

$validation->add('requestedGroupId', new EntityExists([
            'entity' => 'customer_group',
            'context' => $context->getContext(),
            'criteria' => $criteria,
        ]));

        if (!$isGuest) {
            $minLength = $this->systemConfigService->get('core.loginRegistration.passwordMinLength', $context->getSalesChannelId());
            $validation->add('password', new NotBlank(), new Length(['min' => $minLength]));
            $options = ['context' => $context->getContext(), 'salesChannelContext' => $context];
            $validation->add('email', new CustomerEmailUnique($options));
        }

        $validationEvent = new BuildValidationEvent($validation, $data, $context->getContext());
        $this->eventDispatcher->dispatch($validationEvent, $validationEvent->getName());

        return $validation;
    }

    /** * @return array<string, mixed> */
    

private function validateEmail(DataBag $data, SalesChannelContext $context): void
    {
        $validation = new DataValidationDefinition('customer.email.update');

        $options = ['context' => $context->getContext(), 'salesChannelContext' => $context];

        $validation
            ->add(
                'email',
                new Email(),
                new EqualTo(['propertyPath' => 'emailConfirmation']),
                new CustomerEmailUnique($options)
            )
            ->add('password', new CustomerPasswordMatches(['context' => $context]));

        $this->dispatchValidationEvent($validation, $data, $context->getContext());

        $this->validator->validate($data->all(), $validation);

        $this->tryValidateEqualtoConstraint($data->all(), 'email', $validation);
    }

    private function dispatchValidationEvent(DataValidationDefinition $definition, DataBag $data, Context $context): void
    {