20 files declare their use of SmsMessage in SMS Framework 8

AccountRegistration.php in modules/sms_user/src/AccountRegistration.php

DefaultSmsProvider.php in src/Provider/DefaultSmsProvider.php

PhoneNumberProvider.php in src/Provider/PhoneNumberProvider.php

SendToPhoneForm.php in modules/sms_sendtophone/src/Form/SendToPhoneForm.php

SmsDevelMessageForm.php in modules/sms_devel/src/Form/SmsDevelMessageForm.php

SmsDevelMessageTest.php in modules/sms_devel/tests/src/Functional/SmsDevelMessageTest.php

SmsFrameworkBrowserTest.php in tests/src/Functional/SmsFrameworkBrowserTest.php

SmsFrameworkDeliveryReportEntityTest.php in tests/src/Kernel/SmsFrameworkDeliveryReportEntityTest.php

SmsFrameworkGatewayPluginTest.php in tests/src/Kernel/SmsFrameworkGatewayPluginTest.php

SmsFrameworkMessageEntityTest.php in tests/src/Kernel/SmsFrameworkMessageEntityTest.php

SmsFrameworkMessageResultEntityTest.php in tests/src/Kernel/SmsFrameworkMessageResultEntityTest.php

SmsFrameworkProcessorTest.php in tests/src/Kernel/SmsFrameworkProcessorTest.php

SmsFrameworkProviderTest.php in tests/src/Kernel/SmsFrameworkProviderTest.php

SmsFrameworkQueueTest.php in tests/src/Kernel/SmsFrameworkQueueTest.php

SmsFrameworkRecipientGatewayEventTest.php in tests/src/Kernel/SmsFrameworkRecipientGatewayEventTest.php

SmsFrameworkUpdateTest.php in tests/src/Functional/SmsFrameworkUpdateTest.php

SmsFrameworkUserAccountRegistrationServiceTest.php in modules/sms_user/tests/src/Kernel/SmsFrameworkUserAccountRegistrationServiceTest.php

SmsFrameworkUserActiveHoursServiceTest.php in modules/sms_user/tests/src/Kernel/SmsFrameworkUserActiveHoursServiceTest.php

SmsFrameworkUserTest.php in modules/sms_user/tests/src/Kernel/SmsFrameworkUserTest.php

SmsFrameworkViewsTest.php in tests/src/Kernel/SmsFrameworkViewsTest.php