src/Message.php
public function setAttachment($type, $payload)
    {
        $attachment = new Attachment();

        $attachment->setType($type);
        $attachment->setPayload($payload);

        $this->attachment = $attachment;
    }
public function setAttachment($type, $payload)
    {
        $attachment = new Attachment();

        $attachment->setType($type);
        $attachment->setPayload($payload);

        $this->attachment = $attachment;
    }
Set attachment

@param string $type Type
@param array $payload Payload