import java.util.Deque;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.LinkedHashSet;
import java.util.Map;
import java.util.Set;
import java.util.TreeMap;

class ModelGraph {
    private enum PendingState {
        ADD, NOTIFY
    }

    private final ModelNodeInternal root;
    private final Map<ModelPath, ModelNodeInternal> flattened = new TreeMap<>();

        modelGraph = new ModelGraph(new ModelElementNode(this, rootRegistration, null));
        ruleBindings = new RuleBindings();
        transition(modelGraph.getRoot(), Created, false);
    }

    @Override
    public String getProjectPath() {
        return projectPath;
    }

import org.gradle.model.internal.core.ModelNode.State
import org.gradle.model.internal.core.ModelPath
import org.gradle.model.internal.core.MutableModelNode

class ModelGraphTest extends RegistrySpec {
    def graph = new ModelGraph(root())
    def nodes = [:]

    def setup() {
        nodes[graph.root.path] = graph.root
    }

    def "notifies listener when node added"() {
        def listener = allAcceptingListener()

Class <org.gradle.model.internal.registry.ModelGraph$PendingState> is not annotated (directly or via its package) with @org.gradle.api.NonNullApi in (ModelGraph.java:0)
Class <org.gradle.model.internal.registry.ModelGraph> is not annotated (directly or via its package) with @org.gradle.api.NonNullApi in (ModelGraph.java:0)