private boolean hasRexOver(List<RexNode> projects) {
      for(RexNode expr : projects) {
        if(expr instanceof  RexOver) {
          return true;
        }
      }
      return false;
    }
Returns whether there are any correlating variables in this statement.

@return whether there are any correlating variables
ql/src/java/org/apache/hadoop/hive/ql/optimizer/calcite/rules/HiveRelDecorrelator.java