return getExecutionPlanItems().iterator();
    }

    /**
     * Returns the last ExecutionPlanItem in the supplied phase. If no items are in the specified phase,
     * the closest executionPlanItem from an earlier phase item will be returned.
     *
     * @param requestedPhase the requested phase
     *                       The execution plan item
     * @return The ExecutionPlanItem or null if none can be found
     */

    if (seenExceptionsLocal == null) {
      // TODO(cpovirk): Should we use a simpler (presumably cheaper) data structure?
      /*
       * Using weak references here could let us release exceptions earlier, but:
       *
       * 1. On Android, querying a WeakReference blocks if the GC is doing an otherwise-concurrent
       * pass.
       *

/**
 * Instances of this interface retrieve and store data for the --resume / -r feature. This data is used to ensure newer
 * builds of the same project, that have the -r command-line flag, skip successfully built projects during earlier
 * invocations of Maven.
 */
public interface BuildResumptionDataRepository {
    /**
     * Persists any data needed to resume the build at a later point in time, using a new Maven invocation. This method

        // Why? The second half of condition2 requires that nodeV equals other.nodeU.
        // We already know that nodeU equals other.nodeU. Combined with the earlier statement,
        // and the transitive property of equality, this implies that nodeU equals nodeV.
        // If nodeU equals nodeV, condition1 == condition2, so checking condition1 is sufficient.

/**
 * Provides backwards compatibility with Maven 3.2.3 and earlier. Clients that do not require compatibility with Maven
 * 3.2.3 and earlier are encouraged to use {@link JavaToolchainImpl}.
 * <strong>Note:</strong> This is an internal component whose interface can change without prior notice.
 *
 * @deprecated clients that do not require compatibility with Maven 3.2.3 and earlier should link to
 *             {@link JavaToolchainImpl} instead.
 */

        if (model == null) {
            return null;
        }

        // use DefaultJavaToolChain for compatibility with maven 3.2.3 and earlier

        @SuppressWarnings("deprecation")
        JavaToolchainImpl jtc = new DefaultJavaToolChain(model, logger);

        // populate the provides section
        Properties provides = model.getProvides();