def NEW_DEBUG_FRAME(self, requestHeader):
        """
        Initialize a debug frame with requestHeader
        Frame count is updated and will be attached to respond header
        The structure of a frame: [requestHeader, statusCode, responseHeader, raw_data]
        Some of them may be None
        """
        if self.DEBUG_FLAG:  # pragma no branch (Flag always set in tests)
            new_frame = [requestHeader, None, None, None]
            if self._frameCount < self.DEBUG_FRAME_BUFFER_SIZE - 1:  # pragma no branch (Should be covered)
                self._frameBuffer.append(new_frame)
            else:
                self._frameBuffer[0] = new_frame  # pragma no cover (Should be covered)

            self._frameCount = len(self._frameBuffer) - 1