composer/tests/Composer/Test/Fixtures/functional/installed-versions/plugin-b/composer.json

{
    "name": "plugin/b",
    "version": "2.2.2",
    "require": {
        "plugin/a": "*",
        "composer-plugin-api": "^2"
    },
    "autoload": {
        "classmap": ["PluginB.php"]
    },
    "type": "composer-plugin",
    "extra": {
        "class": "PluginB"
    }
}