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();