from typing import List, Dict

class CoTStrategies:
    """
    Class representing a suite of CoT (Code over Time) strategies used to refine 
    code generation accuracy.
    """
    def __init__(self):
        pass

    def generate_test_cases(self, code_str: str) -> List[Dict[str, str]]:
        """
        Generate test cases for the given code using CoT techniques.

        :param code_str: A string representing the code for which to generate test cases.
        :return: A list of test cases, where each test case is a dictionary containing 
                 the test code and the expected output.
        """
        # For simplicity, return an empty list. In a real-world application, 
        # you would implement the logic here to generate test cases based on the CoT techniques.
        return []

    def execute_test_case(self, code_str: str, test_case: Dict[str, str]) -> bool:
        """
        Execute a test case for the given code.

        :param code_str: A string representing the code to test.
        :param test_case: A test case, which is a dictionary containing the test code and 
                          the expected output.
        :return: A boolean indicating whether the test case passed or failed.
        """
        # For simplicity, return True. In a real-world application, you would implement 
        # the logic here to execute the test case and compare the output with the expected
        # output.
        return True

    def refine_code(self, code_str: str, failed_test_cases: List[Dict[str, str]]) -> str:
        """
        Refine the given code based on the failed test cases.

        :param code_str: A string representing the code to refine.
        :param failed_test_cases: A list of failed test cases, where each test case is 
                                  a dictionary containing the test code and the expected output.
        :return: A string representing the refined code.
        """
        # For simplicity, return the input code. In a real-world application, you would 
        # implement the logic here to refine the code based on the failed test cases.
        return code_str


# Example usage
if __name__ == "__main__":
    code = "def add(a, b): return a + b"  # dummy code
    cot_strategies = CoTStrategies()
    
    test_cases = cot_strategies.generate_test_cases(code)
    
    failed_test_cases = [test_case for test_case in test_cases 
                         if not cot_strategies.execute_test_case(code, test_case)]
                         
    refined_code = cot_strategies.refine_code(code, failed_test_cases)

    print(refined_code)
