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