SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function toUInt8 (children 1)
     ExpressionList (children 1)
      Function assumeNotNull (children 1)
       ExpressionList (children 1)
        Function CAST (children 1)
         ExpressionList (children 2)
          Function CAST (children 1)
           ExpressionList (children 2)
            Literal NULL
            Literal \'Nullable(String)\'
          Literal \'Nullable(Enum8(\\\'Hello\\\' = 1))\'