* In a package hierarchy, the {@linkplain #descriptors} map has either zero or one entry.
     * In a module hierarchy, the descriptors map may have an arbitrary number of entries,
     * including one (so the map size cannot be used as a criterion).
     *
     * @see #isModuleHierarchy()
     */
    private final boolean isModuleHierarchy;

    /**

                for (MetadataGraphEdge e : ins) {
                    sb.append("       from :  ").append(e.toString()).append('\n');
                }
            } else {
                sb.append("      no entries\n");
            }

            List<MetadataGraphEdge> outs = getExcidentEdges(v);
            if (outs != null) {
                for (MetadataGraphEdge e : outs) {

     * In a package hierarchy, the {@linkplain #descriptors} map has either zero or one entry.
     * In a module hierarchy, the descriptors map may have an arbitrary number of entries,
     * including one (so the map size cannot be used as a criterion).
     *
     * @see #isModuleHierarchy()
     */
    private final boolean isModuleHierarchy;

    /**

     * management entries in their POMs. Maven 3 targeted full backward compatibility with Maven2, hence it ignored
     * dependency management entries in transitive dependency POMs. Maven 4 enables "transitivity" by default, hence
     * unlike Maven2, obeys dependency management entries deep in dependency graph as well.
     * <p>
     * Default: {@code "true"}.
     *

    void testMirrorStopOnFirstMatch() {
        // exact matches win first
        Mirror mirrorA2 = newMirror("a2", "a,b", "http://a2");
        Mirror mirrorA = newMirror("a", "a", "http://a");
        // make sure repeated entries are skipped
        Mirror mirrorA3 = newMirror("a", "a", "http://a3");

        Mirror mirrorB = newMirror("b", "b", "http://b");
        Mirror mirrorC = newMirror("c", "d,e", "http://de");