85   const after = produce(createEmptyState(), draft => {  constant
88   expect(after.route).toBe('/foo');
184   const after = produce(state, draft => {  constant
192   expect(after.pinnedTracks).toEqual(['a']);
193   expect(after.scrollingTracks).toEqual(['b', 'c']);
200   const after = produce(state, draft => {  constant
208   expect(after.pinnedTracks).toEqual(['a', 'b']);
209   expect(after.scrollingTracks).toEqual(['c']);
216   const after = produce(state, draft => {  constant
223   expect(after).toEqual(state);
230   const after = produce(state, draft => {  constant
237   expect(after).toEqual(state);
244   const after = produce(state, draft => {  constant
249   expect(after.pinnedTracks).toEqual(['a', 'c']);
250   expect(after.scrollingTracks).toEqual(['b']);
257   const after = produce(state, draft => {  constant
262   expect(after.pinnedTracks).toEqual(['b']);
263   expect(after.scrollingTracks).toEqual(['a', 'c']);
270   const after = produce(state, draft => {  constant
276   const engineKeys = Object.keys(after.engines);
277   expect(after.nextId).toBe(101);
279   expect((after.engines[engineKeys[0]].source as TraceUrlSource).url)
281   expect(after.route).toBe('/viewer');
282   expect(after.recordConfig).toBe(recordConfig);
328   const after = produce(state, draft => {  constant
335   expect(after.engines['100'].ready).toBe(true);
346   const after = produce(state, draft => {  constant
352   expect(after.trackGroups['g'].tracks).toEqual(['a', 'b', 'b']);
385   const after = produce(state, draft => {  constant
394   expect(after.trackGroups['g'].tracks)
423   const after = produce(state, draft => {  constant
427   expect(after.trackGroups['g'].tracks).toEqual(['a', 'a', 'c', 'b']);