}

    private ArtifactResolutionResult collect(ArtifactSpec a, Artifact managedVersion)
            throws ArtifactResolutionException {
        Map<String, Artifact> managedVersions =
                Collections.singletonMap(managedVersion.getDependencyConflictId(), managedVersion);
        return artifactCollector.collect(
                Collections.singleton(a.artifact),
                projectArtifact.artifact,

    return (ImmutableMap<K, V>) RegularImmutableMap.EMPTY;
  }

  /**
   * Returns an immutable map containing a single entry. This map behaves and performs comparably to
   * {@link Collections#singletonMap} but will not accept a null key or value. It is preferable
   * mainly for consistency and maintainability of your code.
   */
  public static <K, V> ImmutableMap<K, V> of(K k1, V v1) {
    checkEntryNotNull(k1, v1);

    return (ImmutableMap<K, V>) RegularImmutableMap.EMPTY;
  }

  /**
   * Returns an immutable map containing a single entry. This map behaves and performs comparably to
   * {@link Collections#singletonMap} but will not accept a null key or value. It is preferable
   * mainly for consistency and maintainability of your code.
   */
  public static <K, V> ImmutableMap<K, V> of(K k1, V v1) {