/**
 * Caches extension class realms. <strong>Warning:</strong> This is an internal utility interface that is only public
 * for technical reasons, it is not part of the public API. In particular, this interface can be changed or deleted
 * without prior notice.
 *
 */
public interface ExtensionRealmCache {
    /**
     * A cache key.
     */
    interface Key {
        // marker interface for cache keys
    }

    /**

/**
 * Assists in firing execution events. <strong>Warning:</strong> This is an internal utility class that is only public
 * for technical reasons, it is not part of the public API. In particular, this class can be changed or deleted without
 * prior notice.
 *
 */
@Named
@Singleton
public class DefaultExecutionEventCatapult implements ExecutionEventCatapult {

    @Override

import org.apache.maven.project.MavenProject;

/**
 * <p>
 * Context of dependency artifacts for a particular project.
 * </p>
 * <strong>NOTE:</strong> This class is not part of any public api and can be changed or deleted without prior notice.
 *
 * @since 3.0
 */
// TODO From a concurrency perspective, this class is not good. The combination of mutable/immutable state is not nice
public class DependencyContext {

        if (!keptAccessors.isEmpty()) {
            String formattedLeft = CollectionUtils.join("\n", keptAccessors.keySet());
            throw new RuntimeException("The following accessors were upgraded, but didn't match any removed/changed method:\n\n" + formattedLeft);
        }

        // Find accessors that were removed but shouldn't be
        Map<AccessorKey, ReplacedAccessor> removedAccessors = new HashMap<>(oldAccessorsOfUpgradedProperties);

/**
 * Assists in firing execution events. <strong>Warning:</strong> This is an internal utility interface that is only
 * public for technical reasons, it is not part of the public API. In particular, this interface can be changed or
 * deleted without prior notice.
 *
 */
public interface ExecutionEventCatapult {

    void fire(ExecutionEvent.Type eventType, MavenSession session, MojoExecution mojoExecution);

public class AbstractSetTester<E> extends AbstractCollectionTester<E> {
  /*
   * Previously we had a field named set that was initialized to the value of
   * collection in setUp(), but that caused problems when a tester changed the
   * value of set or collection but not both.
   */
  protected final Set<E> getSet() {
    return (Set<E>) collection;
  }

func TestSetAndGet(t *testing.T) {
	if value, ok := DB.Set("hello", "world").Get("hello"); !ok {
		t.Errorf("Should be able to get setting after set")
	} else if value.(string) != "world" {
		t.Errorf("Set value should not be changed")
	}

	if _, ok := DB.Get("non_existing"); ok {
		t.Errorf("Get non existing key should return error")
	}

			// or deleted by any user, including the root user in your AWS account.
			// When an object is locked in compliance mode, its retention mode can't
			// be changed, and its retention period can't be shortened. Compliance mode
			// ensures that an object version can't be overwritten or deleted for the
			// duration of the retention period.
			t, err := objectlock.UTCNowNTP()

/**
 * Caches plugin artifacts. <strong>Warning:</strong> This is an internal utility interface that is only public for
 * technical reasons, it is not part of the public API. In particular, this interface can be changed or deleted without
 * prior notice.
 *
 */
public interface PluginArtifactsCache {

    /**
     * A cache key.
     */
    interface Key {
        // marker interface for cache keys
    }

}
```

### 3.2 Witness Event Types
```java
public enum WitnessEventType {
    RESOURCE_CHANGE(1),        // Resource state changed
    CLIENT_MOVE(2),           // Client should move to different node
    SHARE_MOVE(3),            // Share moved to different node
    IP_CHANGE(4),             // IP address changed
    SHARE_DELETE(5),          // Share deleted
    NODE_UNAVAILABLE(6),      // Cluster node unavailable