code: public String getParentFolderType(String rootPath) {
  
          String parent = CmsResource.getParentFolder(rootPath);
          if (parent == null) {
              return null;
          }
          String type = m_folderTypes.get(parent);
          // type may be null
          return type;
      }
docs: Helper method to retrieve the parent folder type or <code>null</code> if none available.<p>
  
  @param rootPath the path of a resource
  @return the parent folder content type