hunk.code_window:       function callback(this: { datum: number }, cb: Function) {
           cb(this.datum);
         }
         const boundCallback = bindCallback(callback, rxTestScheduler);
         const results: Array<string|number> = [];
         boundCallback.apply({ datum: 5 })
           .subscribe(
             (x: number) => results.push(x),
  
hunk.labels: keep keep keep keep replace keep keep keep keep keep
hunk.after_edit:       const boundCallback = bindCallback<number>(callback, rxTestScheduler);
  
hunk.file_path: spec/observables/bindCallback-spec.ts
hunk.type: replace
file: import { of, asyncScheduler } from 'rxjs';
  import { timestamp } from 'rxjs/operators';
  
  it('should infer correctly', () => {
    const o = of('a', 'b', 'c').pipe(timestamp()); // $ExpectType Observable<Timestamp<string>>
  });
  
  it('should support a scheduler', () => {
    const o = of('a', 'b', 'c').pipe(timestamp(asyncScheduler)); // $ExpectType Observable<Timestamp<string>>
  });
  
  it('should enforce scheduler type', () => {
    const o = of('a', 'b', 'c').pipe(timestamp('nope')); // $ExpectError
  });
  