}
            if (!(obj instanceof GAKey)) {
                return false;
            }

            GAKey other = (GAKey) obj;
            return Objects.equals(artifactId, other.artifactId) && Objects.equals(groupId, other.groupId);
        }
    }

import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;

import org.apache.maven.model.Model;
import org.apache.maven.model.building.DefaultTransformerContext.GAKey;
import org.apache.maven.model.building.DefaultTransformerContext.Holder;

/**
 * Builds up the transformer context.
 * After the buildplan is ready, the build()-method returns the immutable context useful during distribution.