code: public static boolean hasMixin(final Node node) {
          try {
              return node.isNodeType(FEDORA_WEBAC_ACL);
          } catch (final RepositoryException e) {
              throw new RepositoryRuntimeException(e);
          }
      }
docs: Check if the JCR node has a webac:Acl mixin
  @param node the JCR node
  @return true if the JCR node has the webac:Acl mixin