SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function isNullable (children 1)
     ExpressionList (children 1)
      Function toNullable (children 1)
       ExpressionList (children 1)
        Function toLowCardinality (children 1)
         ExpressionList (children 1)
          Function materialize (children 1)
           ExpressionList (children 1)
            Literal UInt64_1
