@Override
                                      public Binding varVar(final PsiTypeVariable x, final PsiTypeVariable y) {
                                        final int xi = x.getIndex();
                                        final int yi = y.getIndex();

                                        if (xi < yi) {
                                          return create(x, y);
                                        }
                                        else if (yi < xi) {
                                          return create(y, x);
                                        }
                                        else {
                                          return create();
                                        }
                                      }
@Override
                                      public Binding varVar(final PsiTypeVariable x, final PsiTypeVariable y)