Sets the ID of current the operation.
import Batch = require("nativescript-batch");
var b = Batch.newBatch(function(ctx) {
console.log("ID: " + ctx.id); // "operation-1"
}).setId("operation-1")
.then(function(ctx) {
console.log("ID: " + ctx.id); // "operation-2"
}).setId("operation-2");
b.start();