SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function CAST (children 1)
     ExpressionList (children 2)
      Literal Tuple_(Tuple_(\'abc\', UInt64_22), Tuple_(\'def\', UInt64_33))
      Literal \'Map(String, UInt8)\'
