* For example, resolves "[3.8,4.0)" to "3.8", "3.8.1", "3.8.2".
     * The returned list of versions is only dependent on the configured repositories and their contents.
     * The supplied request may also refer to a single concrete version rather than a version range.
     * In this case though, the result contains simply the (parsed) input version, regardless of the
     * repositories and their contents.
     *

    /*
     * TODO(lowasser): consider checking for ImmutableAsList here
     * TODO(lowasser): consider checking for Multiset here
     */
    // Don't refer to ImmutableSortedSet by name so it won't pull in all that code
    if (elements instanceof ImmutableSet && !(elements instanceof SortedSet)) {
      @SuppressWarnings("unchecked") // all supported methods are covariant

 * is meant for exclusive consumption by the model builder and is opaque to the cache implementation. The cache key is
 * formed by a combination of group id, artifact id, version and tag. The first three components generally refer to the
 * identity of a model. The tag allows for further classification of the associated data on the sole discretion of the
 * model builder.
 *
 */
public interface ModelCache {