SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 2)
    Function if (alias x) (children 1)
     ExpressionList (children 3)
      Function equals (children 1)
       ExpressionList (children 2)
        Literal UInt64_1
        Literal UInt64_1
      Literal NULL
      Function toNullable (children 1)
       ExpressionList (children 1)
        Function toUInt8 (children 1)
         ExpressionList (children 1)
          Literal UInt64_0
    Function toTypeName (children 1)
     ExpressionList (children 1)
      Identifier x