11 classes are annotated with Plugin

Apple in core/modules/system/tests/modules/plugin_test/src/Plugin/plugin_test/fruit/Apple.php
Plugin annotation @Plugin( id = "apple", label = "Apple", color = "green" )
Banana in core/modules/system/tests/modules/plugin_test/src/Plugin/plugin_test/fruit/Banana.php
Plugin annotation @Plugin( id = "banana", label = "Banana", color = "yellow", uses = { "bread" = @Translation("Banana bread"), "loaf" = @PluralTranslation( singular = "@count loaf", plural = "@count loaves" ) } )
Broccoli in core/tests/Drupal/Tests/Component/Plugin/Fixtures/vegetable/Broccoli.php
Plugin annotation @Plugin( id = "broccoli", label = "Broccoli", color = "green" )
Cherry in core/modules/system/tests/modules/plugin_test/src/Plugin/plugin_test/fruit/Cherry.php
Plugin annotation @Plugin( id = "cherry", label = "Cherry", color = "red" )
Corn in core/tests/Drupal/Tests/Component/Plugin/Fixtures/vegetable/Corn.php
Plugin annotation @Plugin( id = "corn", label = "Corn", color = "yellow" )
CustomDirectoryExample1 in core/modules/system/tests/modules/plugin_test/src/CustomDirectoryExample1.php
Provides a test plugin within a custom directory.
CustomDirectoryExample2 in core/modules/system/tests/modules/plugin_test/src/CustomDirectoryExample2.php
Provides a test plugin within a custom directory.
DiscoveryTest1 in core/tests/Drupal/Tests/Component/Annotation/Fixtures/PluginNamespace/DiscoveryTest1.php
Provides a custom test plugin.
ExtendingNonInstalledClass in core/modules/system/tests/modules/plugin_test/src/Plugin/plugin_test/fruit/ExtendingNonInstalledClass.php
Plugin annotation @Plugin( id = "extending_non_installed_class", label = "A plugin whose class is extending from a non-installed module class", color = "pink", )
Kale in core/modules/system/tests/modules/plugin_test/src/Plugin/plugin_test/fruit/Kale.php
Plugin annotation @Plugin( id = "kale", label = "Kale", color = "green" )
Orange in core/modules/system/tests/modules/plugin_test/src/Plugin/plugin_test/fruit/Orange.php
Plugin annotation @Plugin( id = "orange", label = "Orange", color = "orange" )

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