SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 3)
    Function if (alias x) (children 1)
     ExpressionList (children 3)
      Function equals (children 1)
       ExpressionList (children 2)
        Function CAST (children 1)
         ExpressionList (children 2)
          Literal NULL
          Literal \'Nullable(UInt8)\'
        Literal UInt64_1
      Function CAST (children 1)
       ExpressionList (children 2)
        Literal NULL
        Literal \'Nullable(UInt8)\'
      Literal Int64_-1
    Function toTypeName (children 1)
     ExpressionList (children 1)
      Identifier x
    Function dumpColumnStructure (children 1)
     ExpressionList (children 1)
      Identifier x