code: public final void commit() {
          ensureNotYetCreated();
          ensureHasChanges();
          alreadyCreated = true;
          area.replaceMulti(Collections.unmodifiableList(list));
      }
docs: Applies all the changes stored in this object to the underlying document of the area. <strong>Note: this builder
  cannot be reused and a new one must be created for each multi-change.</strong>