code: private CmsMessageBundleEditorTypes.BundleType initBundleType() {
  
          String resourceTypeName = OpenCms.getResourceManager().getResourceType(m_resource).getTypeName();
          return CmsMessageBundleEditorTypes.BundleType.toBundleType(resourceTypeName);
      }
docs: Init the bundle type member variable.
  @return the bundle type of the opened resource.