def _on_request(self, adapter, request, **kwargs):
        match = self._find_match(request)
        # TODO(dcramer): find the correct class for this
        if match is None:
            error_msg = 'Connection refused: {0} {1}'.format(request.method,
                                                             request.url)
            response = ConnectionError(error_msg)
            response.request = request

            self._calls.add(request, response)
            raise response

        if 'body' in match and isinstance(match['body'], Exception):
            self._calls.add(request, match['body'])
            raise match['body']

        headers = {
            'Content-Type': match['content_type'],
        }

        if 'callback' in match:  # use callback
            status, r_headers, body = match['callback'](request)
            if isinstance(body, six.text_type):
                body = body.encode('utf-8')
            body = BufferIO(body)
            headers.update(r_headers)

        elif 'body' in match:
            if match['adding_headers']:
                headers.update(match['adding_headers'])
            status = match['status']
            body = BufferIO(match['body'])

        response = HTTPResponse(
            status=status,
            body=body,
            headers=headers,
            preload_content=False,
        )

        response = adapter.build_response(request, response)
        if not match.get('stream'):
            response.content  # NOQA

        try:
            resp_cookies = Cookies.from_request(response.headers['set-cookie'])
            response.cookies = cookiejar_from_dict(dict(
                (v.name, v.value)
                for _, v
                in resp_cookies.items()
            ))
        except (KeyError, __HOLE__):
            pass

        self._calls.add(request, response)

        return response
dataset/ETHPy150Open getsentry/responses/responses.py/RequestsMock._on_request