9 files declare their use of ResponseInterface in Payment 8.2

CompletePaymentTest.php in tests/src/Unit/Controller/CompletePaymentTest.php

OperationResult.php in src/OperationResult.php

OperationResultTest.php in tests/src/Unit/OperationResultTest.php

PaymentCaptureFormTest.php in tests/src/Unit/Entity/Payment/PaymentCaptureFormTest.php

PaymentFormTest.php in modules/payment_form/tests/src/Unit/Entity/Payment/PaymentFormTest.php

PaymentFormTest.php in modules/payment_form/tests/src/Unit/Plugin/Payment/Type/PaymentFormTest.php

PaymentReferenceTest.php in modules/payment_reference/tests/src/Unit/Plugin/Payment/Type/PaymentReferenceTest.php

PaymentRefundFormTest.php in tests/src/Unit/Entity/Payment/PaymentRefundFormTest.php

PaymentTypeBaseTest.php in tests/src/Unit/Plugin/Payment/Type/PaymentTypeBaseTest.php