nit

lm_eval/api/instance.py

 from dataclasses import dataclass, field
 from typing import Literal, Optional, Tuple
 
-from lm_eval.api.types import GenerateUntilRequest, LogLiklehoodRequest
-
 
 OutputType = Literal[
     "loglikelihood", "loglikelihood_rolling", "generate_until", "multiple_choice"
@@ -36,7 +34,5 @@ class Instance:
         Returns (string,) where `string` is the string to calculate loglikelihood over
         """
         return (
-            GenerateUntilRequest(*self.arguments)
-            if self.request_type != "generate_until"
-            else LogLiklehoodRequest(*self.arguments)
+            self.arguments if isinstance(self.arguments, tuple) else (self.arguments,)
         )