SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function JSONExtract (children 1)
     ExpressionList (children 3)
      Function materialize (children 1)
       ExpressionList (children 1)
        Function toLowCardinality (children 1)
         ExpressionList (children 1)
          Literal \'{"string_value":null}\'
      Function materialize (children 1)
       ExpressionList (children 1)
        Literal \'string_value\'
      Literal \'LowCardinality(Nullable(String))\'
