public boolean isEmpty() {
    // TODO: cache the value
    for (int i = 0; i < deleted.length; ++i) {
      if (deleted[i] != WORD_MASK) {
        return false;
      }
    }
    return true;
  }
Returns true, if there are no active procedures in this BitSetNode, else false.
hbase-procedure/src/main/java/org/apache/hadoop/hbase/procedure2/store/wal/BitSetNode.java