*       the upper bound is implicitly an Enum too).
   *   <li>If {@code canonicalize(A) == canonicalize(B)}, then {@code Foo<A>.isSubtypeOf(Foo<B>)}
   *       and vice versa. i.e. {@code A.is(B)} and {@code B.is(A)}.
   *   <li>{@code canonicalize(canonicalize(A)) == canonicalize(A)}.
   * </ol>
   */
  private static Type canonicalizeTypeArg(TypeVariable<?> declaration, Type typeArg) {

    return multimap.asMap();
  }

  /**
   * Returns a multimap view of the specified map. The multimap is backed by the map, so changes to
   * the map are reflected in the multimap, and vice versa. If the map is modified while an
   * iteration over one of the multimap's collection views is in progress (except through the
   * iterator's own {@code remove} operation, or through the {@code setValue} operation on a map