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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _response_value(self, response, json=True):
 """Parses the HTTP response as a the cloudstack value. It throws an exception if the server didn't answer with a 200. """

        if json:
            contentType = response.headers.get("Content-Type", "")
            if not contentType.startswith(("application/json",
                                           "text/javascript")):
                if response.status_code == 200:
                    raise CloudStackException(
                        "JSON (application/json) was expected, got {!r}"
                        .format(contentType),
                        response=response)

                raise CloudStackException(
                    "HTTP {0.status_code} {0.reason}"
                    .format(response),
                    "Make sure endpoint URL {!r} is correct."
                    .format(self.endpoint),
                    response=response)

            try:
                data = response.json()
            except ValueError as e:
                raise CloudStackException(
                    "HTTP {0.status_code} {0.reason}"
                    .format(response),
                    "{0!s}. Malformed JSON document".format(e),
                    response=response)

            [key] = data.keys()
            data = data[key]
        else:
            data = response.text

        if response.status_code != 200:
            raise CloudStackException(
                "HTTP {0} response from CloudStack".format(
                    response.status_code),
                data,
                response=response)

        return data