6 files declare their use of StaticDiscovery

CacheDecoratorTest.php in drupal/core/modules/system/lib/Drupal/system/Tests/Plugin/CacheDecoratorTest.php
Contains \Drupal\system\Tests\Plugin\CacheDecoratorTest.
DefaultsTestPluginManager.php in drupal/core/modules/system/tests/modules/plugin_test/lib/Drupal/plugin_test/Plugin/DefaultsTestPluginManager.php
Contains Drupal\plugin_test\Plugin\DefaultsTestPluginManager.
MockBlockManager.php in drupal/core/modules/system/tests/modules/plugin_test/lib/Drupal/plugin_test/Plugin/MockBlockManager.php
Definition of Drupal\plugin_test\Plugin\MockBlockManager.
PluginBaseUnitTest.php in drupal/core/modules/views/lib/Drupal/views/Tests/PluginBaseUnitTest.php
Contains \Drupal\views\Tests\PluginBaseUnitTest.
StaticDiscoveryTest.php in drupal/core/modules/system/lib/Drupal/system/Tests/Plugin/Discovery/StaticDiscoveryTest.php
Definition of Drupal\system\Tests\Plugin\Discovery\StaticDiscoveryTest.
TestPluginManager.php in drupal/core/modules/system/tests/modules/plugin_test/lib/Drupal/plugin_test/Plugin/TestPluginManager.php
Definition of Drupal\plugin_test\Plugin\TestPluginManager.