public function trigger($campaignId, $email, array $tokens)
    {
        $lead = $this->client->leads()->show($email);
        $tokens = $this->parseTokens($tokens);
        $response = $this->post($this->client->url . "/rest/v1/campaigns/$campaignId/trigger.json",
            [
                'input' => [
                    'leads' => [
                        ['id' => $lead->id]
                    ],
                    'tokens' => $tokens
                ]
            ]
        );

        if (!$response->success) {
            throw new MarketoApiException('Error triggering campaign: ' . $response->errors[0]->message);
        }
    }