code: def __call__(
      self,
      task_state: TaskState,
      **kwargs,
  ) -> SolverResult:
      past_messages = (
          task_state.messages
          if not self.persistent_memory
          else self._persistent_memory_past_messages(task_state)
      )
  
      # Reasoning step
      msgs = (
          [
              {
                  "role": "system",
                  "content": task_state.task_description,
              },
          ]
          + [msg.to_dict() for msg in past_messages]
          + [
              {"role": "system", "content": self.cot_template},
          ]
      )
      reasoning_output = self.cot_completion_fn(
          prompt=msgs, **kwargs
      ).get_completions()[0]
  
      # Extract answer step
      msgs = msgs + [
          {"role": "assistant", "content": reasoning_output},
          {"role": "assistant", "content": self.extract_template},
      ]
      extracted_answer = self.extract_completion_fn(
          prompt=msgs, **kwargs
      ).get_completions()[0]
  
      #   Save the interaction
      interaction_messages = [Message(**msg) for msg in msgs[1:]] + [
          Message("assistant", extracted_answer)
      ]
      num_interaction_messages = len(interaction_messages)
      private_messages_ids = (
          []
          if self.last_interaction is None
          else self.last_interaction.private_messages_ids
      )
      private_messages_ids += list(
          range(
              num_interaction_messages
              - self.private_interaction_length
              - 1,
              num_interaction_messages - 1,
          )
      )
      self.last_interaction = Interaction(
          interaction_messages, private_messages_ids
      )
  
      return SolverResult(
          output=extracted_answer,
          reasoning_output=reasoning_output,
      )
  
file_path: evals/evals/solvers/openai_chat_completion_cot_solver.py
imports: from dataclasses import dataclass
  from typing import Any, Dict, List, Union
  from evals.completion_fns.openai import OpenAIChatCompletionFn
  from evals.solvers.prompts.cot import DEFAULT_COT_TEMPLATE, DEFAULT_EXTRACT_ANSWER_TEMPLATE
  from evals.solvers.solver import OpenAISolver, SolverResult
  from evals.task_state import Message, TaskState
label_desc: Use image node_id 2 for calling the OpenAIChatCompletionCoTSolver obj's underlying member method code with example usage: obj.__call__(task_state) and returns: SolverResult