hunk.code_window:   const path2 = ['bar', 'baz'];
     const b = of(obj).pipe(pluck('foo', ...path2)); // $ExpectType Observable<unknown>
   });
  
hunk.labels: keep keep keep add
hunk.after_edit: it('should support arrays', () => {
     const a = of(['abc']).pipe(pluck(0)) // $ExpectType Observable<string>
   })
   it('should support picking by symbols', () => {
     const sym = Symbol('sym')
     const a = of({ [sym]: 'abc' }).pipe(pluck(sym)) // $ExpectType Observable<string>
   })
hunk.file_path: spec-dtslint/operators/pluck-spec.ts
hunk.type: add
file: import { build } from './build';
  import { mockFlatApiList, mockRawTreeNodes } from './fixtures';
  import { treeNodeCount } from './helpers';
  
  describe('build', () => {
    const tree = build(mockFlatApiList, mockRawTreeNodes);
    it('should return a flat map of all nodes and one additional initial node', () => {
      expect(tree).toHaveProperty('initial');
      expect(Object.keys(tree).length).toBe(treeNodeCount(mockRawTreeNodes) + 1);
    });
  });
  