Gets or sets the result for all operations.

import Batch = require("nativescript-batch");

var b = Batch.newBatch(function(ctx) {
    // ctx.prevValue = undefined
    ctx.result = 11;
}).then(function(ctx) {
    // something that does NOT set
    // ctx.result property
}).then(function(ctx) {
    ++ctx.result;
}).then(function(ctx) {
    ++ctx.result;
}).then(function(ctx) {
    // something that does NOT set
    // ctx.result property
});

// 13
var r = b.start();