import { Observable } from "rxjs/Observable";
import { _throw } from "rxjs/observable/throw";
import "rxjs/add/observable/throw";

const ob1 = Observable.throw("Boom!");
                             ~~~~~~~                [throw-error]
const ob2 = Observable.throw(new Error("Boom!"));
const ob3 = _throw("Boom!");
                   ~~~~~~~                          [throw-error]
const ob4 = _throw(new Error("Boom!"));

// There will be no signature for callback and
// that should not effect and internal error.
declare const callback: Function;
callback();

[throw-error]: Passing non-Error values is forbidden