7 files declare their use of DevelGenerateBase in Devel 8

ContentDevelGenerate.php in devel_generate/src/Plugin/DevelGenerate/ContentDevelGenerate.php

devel_generate.module in devel_generate/devel_generate.module

ExampleDevelGenerate.php in devel_generate/tests/modules/devel_generate_example/src/Plugin/DevelGenerate/ExampleDevelGenerate.php

MenuDevelGenerate.php in devel_generate/src/Plugin/DevelGenerate/MenuDevelGenerate.php

TermDevelGenerate.php in devel_generate/src/Plugin/DevelGenerate/TermDevelGenerate.php

UserDevelGenerate.php in devel_generate/src/Plugin/DevelGenerate/UserDevelGenerate.php

VocabularyDevelGenerate.php in devel_generate/src/Plugin/DevelGenerate/VocabularyDevelGenerate.php