code: private CmsLock getParentLock(final String absoluteResourcename) {
  
          CmsLock parentFolderLock = getParentFolderLock(absoluteResourcename);
          if (!parentFolderLock.isNullLock()) {
              return parentFolderLock;
          }
          return CmsLock.getNullLock();
      }
docs: Returns the inherited lock of a resource.<p>
  
  @param absoluteResourcename the absolute path of the resource
  
  @return the inherited lock or the null lock