code: public Compactor withDefaultCompactionMode(Compaction.Mode mode) {
      Assert.notNull(mode, "mode");
      Assert.argNot(mode, mode == Compaction.Mode.DEFAULT, "DEFAULT cannot be the default compaction mode");
      this.defaultCompactionMode = mode;
      return this;
    }
docs: Sets the default compaction mode.
  
  @param mode The default compaction mode.
  @return The compactor.
  @throws NullPointerException if the compaction mode is {@code null}
  @throws IllegalArgumentException if the compaction mode is {@link Compaction.Mode#DEFAULT}