知道了这个...如果有人感兴趣，请在此处发布.谢谢！

Got this figured out... posting here in case anyone is ever interested. Thank you!

  public function send($signer_name,$signer_email, $cc_name, $cc_email, $template_id,$email_subject, $extrapdf = null) {
        $this->checkToken();

        //create roles for signers

        $signer1 = new \DocuSign\eSign\Model\Signer([
            'email' => $signer_email, 'name' => $signer_name,
            'role_name' => "Signer 1", 'recipient_id' => "1"
        ]);


        $signer2 = new \DocuSign\eSign\Model\Signer([
            'email' => $cc_email, 'name' => $cc_name,
            'role_name' => "Signer 2", 'recipient_id' => "2"

        ]);

        $recipients_server_template = new \DocuSign\eSign\Model\Recipients([
            'signers' => [$signer1,$signer2]]);


        //create composite template
        $comp_template1 = new \DocuSign\eSign\Model\CompositeTemplate([
            'composite_template_id' => "1",
            'server_templates' => [
                new \DocuSign\eSign\Model\ServerTemplate([
                    'sequence' => "1", 'template_id' => $template_id])
            ],
            # Add the roles via an inlineTemplate
            'inline_templates' => [
                new \DocuSign\eSign\Model\InlineTemplate([
                    'sequence' => "1",
                    'recipients' => $recipients_server_template])
            ]

        ]);

        //create new document to be added
        $doc1_b64 = base64_encode($extrapdf);
        $doc1 = new DocuSign\eSign\Model\Document([
            'document_base64' => $doc1_b64,
            'name' => 'HomeownershipCounseling', # can be different from
                                                 # actual file name
            'file_extension' => 'pdf', 'document_id' =>'1']);

        $comp_template2 = new DocuSign\eSign\Model\CompositeTemplate([
            'composite_template_id' => "2",
            # Add the recipients via an inlineTemplate
            'inline_templates' => [
                new \DocuSign\eSign\Model\InlineTemplate([
                    'sequence' => "2"])
            ],
            'document' => $doc1]);


        //create envelope definition
        $envelop_definition = new DocuSign\eSign\Model\EnvelopeDefinition();
        //set email subject on envelope
        $envelop_definition->setEmailSubject($email_subject);
        $envelop_definition->setCompositeTemplates(array($comp_template1, $comp_template2));
        $envelop_definition->setStatus('sent');
        //create new instance of envelope API
        $envelopeApi = new DocuSign\eSign\Api\EnvelopesApi(self::$apiClient);
        //go ahead and create the envelope at DocuSign
        $results = $envelopeApi->createEnvelope(self::$accountID, $envelop_definition);
        //get the created envelope Envelope ID
        $envelopeId = $results['envelope_id'];


        return $results;
    }