SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function cityHash64 (children 1)
     ExpressionList (children 1)
      Function materialize (children 1)
       ExpressionList (children 1)
        Function array (children 1)
         ExpressionList (children 2)
          Literal Tuple_(UInt64_1, \'c\')
          Literal Tuple_(UInt64_2, \'b\')