old_contents: class CannotOverwriteExistingCassetteException(Exception):
      def __init__(self, *args, **kwargs):
          message = self._get_message(kwargs["cassette"], kwargs["failed_request"])
          super(CannotOverwriteExistingCassetteException, self).__init__(message)
  
      def _get_message(self, cassette, failed_request):
          """Get the final message related to the exception"""
          # Get the similar requests in the cassette that
          # have match the most with the request.
          best_matches = cassette.find_requests_with_most_matches(failed_request)
          # Build a comprehensible message to put in the exception.
          best_matches_msg = ""
          for best_match in best_matches:
              request, _, failed_matchers_assertion_msgs = best_match
              best_matches_msg += "Similar request found : (%r).\n" % request
              for failed_matcher, assertion_msg in failed_matchers_assertion_msgs:
                  best_matches_msg += "Matcher failed : %s\n" "%s\n" % (
                      failed_matcher,
                      assertion_msg,
                  )
          return (
              "Can't overwrite existing cassette (%r) in "
              "your current record mode (%r).\n"
              "No match for the request (%r) was found.\n"
              "%s"
              % (cassette._path, cassette.record_mode, failed_request, best_matches_msg)
          )
  
  
  class UnhandledHTTPRequestError(KeyError):
      """Raised when a cassette does not contain the request we want."""
      pass
  
new_contents: class CannotOverwriteExistingCassetteException(Exception):
      def __init__(self, *args, **kwargs):
          self.cassette = kwargs["cassette"]
          self.failed_request = kwargs["failed_request"]
          message = self._get_message(kwargs["cassette"], kwargs["failed_request"])
          super(CannotOverwriteExistingCassetteException, self).__init__(message)
  
      def _get_message(self, cassette, failed_request):
          """Get the final message related to the exception"""
          # Get the similar requests in the cassette that
          # have match the most with the request.
          best_matches = cassette.find_requests_with_most_matches(failed_request)
          # Build a comprehensible message to put in the exception.
          best_matches_msg = ""
          for best_match in best_matches:
              request, _, failed_matchers_assertion_msgs = best_match
              best_matches_msg += "Similar request found : (%r).\n" % request
              for failed_matcher, assertion_msg in failed_matchers_assertion_msgs:
                  best_matches_msg += "Matcher failed : %s\n" "%s\n" % (
                      failed_matcher,
                      assertion_msg,
                  )
          return (
              "Can't overwrite existing cassette (%r) in "
              "your current record mode (%r).\n"
              "No match for the request (%r) was found.\n"
              "%s"
              % (cassette._path, cassette.record_mode, failed_request, best_matches_msg)
          )
  
  
  class UnhandledHTTPRequestError(KeyError):
      """Raised when a cassette does not contain the request we want."""
      pass
  
subject: Add cassette and failed request as properties of thrown CannotOverwriteCassetteException