@Override
  public boolean equals(Object obj) {
    if (obj instanceof HiveRexExprList) {
      return this.expressions.equals(((HiveRexExprList) obj).expressions);
    }
    return false;
  }
This class represents the equivalent to {@link ExprNodeColumnListDesc}
in a Calcite expression. It is not supposed to be used through planning
and should be immediately expanded after it has been generated by
the parser.
ql/src/java/org/apache/hadoop/hive/ql/optimizer/calcite/reloperators/HiveRexExprList.java