```
 getProcessInstanceVariables(processInstanceId) {
        var options = {
            method: "GET",
            hostname: "localhost",
            port: "9090",
            path: "/activiti-app/api/enterprise/process-instances/" + processInstanceId + "/historic-variables",
            headers: {
                'Authorization': 'Basic YWRtaW5AYXBwLmFjdGl2aXRpLmNvbTphZG1pbg==',
                'Cache-Control': 'no-cache'
            }
        };

        var req = http.get(options, function (res) {
            var chunks = [];
            res.on("data", function (chunk) {
                console.log('coucou')
                chunks.push(chunk);
            });
            res.on("end", function () {
                var body = Buffer.concat(chunks);
                var response = body.toString();
                var test = JSON.parse(response)
                this.processInstanceVariables = test;
                this.processInstanceVariables.forEach(element => {
                    console.log("-----------------------------------------  ");
                    console.log("processInstanceVariables  " + element.id);
                    console.log("processInstanceVariables  " + element.type);
                    console.log("processInstanceVariables  " + element.value);
                    console.log("-----------------------------------------  ");
                });
            });
        });

        req.end();
    }