public function addTextEvidence($id, $contentOrRequest)
    {
        $request = is_array($contentOrRequest) ? $contentOrRequest : ['content' => $contentOrRequest];
        if (trim($request['content']) == "") {
            throw new InvalidArgumentException('content cannot be blank');
        }

        try {
            $evidence = [
                'comments' => $request['content'],
            ];

            if (trim($id) == "") {
                throw new Exception\NotFound();
            }

            if (array_key_exists('tag', $request)) {
                $evidence['category'] = $request['tag'];
            }

            if (array_key_exists('category', $request)) {
                if (trim($request['category']) == "") {
                    throw new InvalidArgumentException('category cannot be blank');
                }
                $evidence['category'] = $request['category'];
            }

            if (array_key_exists('sequenceNumber', $request)) {
                if (trim($request['sequenceNumber']) == "") {
                    throw new InvalidArgumentException('sequenceNumber cannot be blank');
                } else if ((string)(int)($request['sequenceNumber']) != $request['sequenceNumber']) {
                    throw new InvalidArgumentException('sequenceNumber must be an integer');
                }
                $evidence['sequenceNumber'] = (int)$request['sequenceNumber'];
            }

            $path = $this->_config->merchantPath() . '/disputes/' . $id . '/evidence';
            $response = $this->_http->post($path, [
                'evidence' =>  $evidence
            ]);

            if (isset($response['apiErrorResponse'])) {
                return new Result\Error($response['apiErrorResponse']);
            }

            if (isset($response['evidence'])) {
                $evidence = new Dispute\EvidenceDetails($response['evidence']);
                return new Result\Successful($evidence);
            }
        } catch (Exception\NotFound $e) {
            throw new Exception\NotFound('dispute with id "' . $id . '" not found');
        }
    }