code: public boolean isAscending() {
          if (from.isRelative() != to.isRelative()) {
              throw new IllegalStateException("both of from: '" + from + "' and to: '" + to +
                                              "' should be absolute or relative.");
          }
  
          return from.compareTo(to) < 0;
      }
docs: Returns {@code true} if the major value of {@code from} {@link Revision} is lower than the major
  value of {@code to} {@link Revision}.
  
  @throws IllegalStateException if the {@code from} and {@code to} {@link Revision}s are in the
  different state. They should be either absolute or relative.