public Collection<Operator> getAllOps() {
    List<Operator> ops = new ArrayList<>();
    Set<Operator> visited = new HashSet<Operator>();
    for (Operator<?> op : getTopOps().values()) {
      getAllOps(ops, visited, op);
    }
    return ops;
  }
@param opToPartToSkewedPruner
         the opToSkewedPruner to set
ql/src/java/org/apache/hadoop/hive/ql/parse/ParseContext.java