code: public void saveImplementedVersion(Page page, Integer version) {
          Integer previousImplementedVersion = getImplementedVersion(page);
          if (previousImplementedVersion != null && version != null && previousImplementedVersion == version)
              return;
  
          if (previousImplementedVersion != null)
              savePreviousImplementedVersion(page, previousImplementedVersion);
  
          String value = version != null ? String.valueOf(version) : null;
          ContentEntityObject entityObject = getContentEntityManager().getById(page.getId());
          getContentPropertyManager().setStringProperty(entityObject, IMPLEMENTED_VERSION, value);
      }
docs: Saves the sprecified version as the Iimplemented version
  
  @param page a {@link com.atlassian.confluence.pages.Page} object.
  @param version a {@link java.lang.Integer} object.