it('should reset header narrowing', () => {
        const narrowedState = reducer(state.org.present, types.narrowHeader(nestedHeaderId));
        expect(narrowedState.getIn(['files', path, 'narrowedHeaderId'])).toEqual(nestedHeaderId);
        const newState = reducer(narrowedState, types.removeHeader(nestedHeaderId));
        expect(newState.getIn(['files', path, 'narrowedHeaderId'])).toEqual(null);