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