// Enable method enables an Policy at OpsGenie.
func (cli *OpsGeniePolicyClient) Enable(req policy.EnablePolicyRequest) (*policy.EnablePolicyResponse, error) {
	req.APIKey = cli.apiKey
	resp, err := cli.sendRequest(cli.buildPostRequest(enablePolicyURL, req))

	if resp == nil {
		return nil, err
	}
	defer resp.Body.Close()

	var enablePolicyResp policy.EnablePolicyResponse
	if err = resp.Body.FromJsonTo(&enablePolicyResp); err != nil {
		message := "Server response can not be parsed, " + err.Error()
		logging.Logger().Warn(message)
		return nil, errors.New(message)
	}
	return &enablePolicyResp, nil
}