E-signatures with Java

public class PDFSignSimpleExample {
    private CreateEtchPacket getPacketVariables(String pdfTemplateEid, String signerName, String signerEmail) {
        CreateEtchPacket packetPayload = new CreateEtchPacket();
        packetPayload.name = "Test Docs - " + signerName;
        packetPayload.signatureEmailSubject = "Custom email subject";
        packetPayload.signatureEmailBody = "Custom please sign these documents....";

        List<IAttachable> etchFiles = this.getFiles(pdfTemplateEid);
        List<EtchSigner> signers = this.getSigners(signerName, signerEmail);
        PayloadData data = this.getPayloadData(signerName, signerEmail);

        packetPayload.files = etchFiles.toArray(new IAttachable[0]);
        packetPayload.signers = signers.toArray(new EtchSigner[0]);
        packetPayload.data = data;

        return packetPayload;
    }

    public static void main(String[] args) {
        String pdfTemplateId = "B5Loz3C7GVortDmn4p2P";
        String signerName = "Testy Signer";
        String signerEmail = 'testy@signer.com';

        CreateEtchPacket payload = this.getPacketVariables(pdfTemplateId, signerName, signerEmail);

        HttpResponse<String> response = this.callCreateEtchPacket(payload)
        String res = response.body();
    }
}