hunk.code_window:   const a = of({ name: 'abc' }).pipe(pluck()); // $ExpectType Observable<unknown>
   });
   it('should accept string only', () => {
     const a = of({ name: 'abc' }).pipe(pluck(1)); // $ExpectError
   });
  
hunk.labels: keep keep keep replace keep keep keep
hunk.after_edit: it('should not accept a number when plucking an object', () => {
  
hunk.file_path: spec-dtslint/operators/pluck-spec.ts
hunk.type: replace
file: import { of } from 'rxjs';
  import { refCount } from 'rxjs/operators';
  
  it('should infer correctly', () => {
    const a = of(1, 2, 3).pipe(refCount()); // $ExpectType Observable<number>
  });
  
  it('should not accept any parameters', () => {
    const a = of(1, 2, 3).pipe(refCount(1)); // $ExpectError
  });
  