RxJS bindcallback's stream completes after first emit

rxjs-bindCallback-test.js

// jsbin https://jsbin.com/xeyugac/edit?js,console
const { Observable } = Rx;

const testFn = (callback) => {
    callback(1,2);
};

const testFnAsObservable = Observable.bindCallback(testFn);

const obs = testFnAsObservable();

obs.subscribe(
    value => console.log('value', value),
    error => console.error(error),
    () => console.log('complete!')
);

// output
// value [1,2]
// complete!