for (Plugin element : tgt) {
                    Object key = getPluginKey(element);
                    merged.put(key, element);
                }

                Map<Object, Plugin> added = new LinkedHashMap<>();

                for (Plugin element : src) {
                    Object key = getPluginKey(element);
                    Plugin existing = merged.get(key);

                    Object key = getPluginKey(element);
                    master.put(key, element);
                }

                Map<Object, List<Plugin>> predecessors = new LinkedHashMap<>();
                List<Plugin> pending = new ArrayList<>();
                for (Plugin element : src) {
                    Object key = getPluginKey(element);
                    Plugin existing = master.get(key);

                for (Plugin element : src) {
                    Object key = getPluginKey(element);
                    managedPlugins.put(key, element);
                }

                for (Plugin element : tgt) {
                    Object key = getPluginKey(element);
                    Plugin managedPlugin = managedPlugins.get(key);
                    if (managedPlugin != null) {

                        Object key = getPluginKey(element);

                        master.put(key, plugin);
                    }
                }

                Map<Object, List<Plugin>> predecessors = new LinkedHashMap<>();
                List<Plugin> pending = new ArrayList<>();
                for (Plugin element : tgt) {
                    Object key = getPluginKey(element);

        if (build != null) {
            // Check build/plugins - these are the actual plugins used in the build
            for (Plugin plugin : build.getPlugins()) {
                String pluginKey = getPluginKey(plugin);
                PluginUpgrade upgrade = pluginUpgrades.get(pluginKey);
                if (upgrade != null) {
                    String effectiveVersion = plugin.getVersion();

        }
    }

    @Override
    protected Object getDependencyKey(Dependency dependency) {
        return dependency.getManagementKey();
    }

    @Override
    protected Object getPluginKey(Plugin plugin) {
        return plugin.getKey();
    }

    @Override
    protected Object getPluginExecutionKey(PluginExecution pluginExecution) {
        return pluginExecution.getId();
    }

        // TODO
    }

    protected Object getDependencyKey(Dependency dependency) {
        return dependency;
    }

    protected Object getPluginKey(Plugin plugin) {
        return plugin;
    }

    protected Object getPluginExecutionKey(PluginExecution pluginExecution) {
        return pluginExecution;
    }