How can I add an precomputed annotation layer? about neuroglancer HOT 2 OPEN

See this example for writing annotations:
https://github.com/google/neuroglancer/blob/master/python/examples/write_annotations.py

The neuroglancer.write_annotations module doesn't yet use the sharded format so it will create a lot of small files but should be fine as long as you don't have too many annotations.

If you want to associate annotations with segment ids, specify a relationship:

And then use the specified relationship identifier as a keyword argument to add_point.

Finally, be sure to associate the relationship with the corresponding segmentation layer when you add the annotation layer to neuroglancer.

from neuroglancer.

I won't add annotations layer, instead of adding a skeleton layer, Because I have opened a server locally that is specifically used to store precomputed data, when I use Python to add a layer of neuroglancer, the source parameter is the location of my local precomputed data, rather than real-time paintung and rendering. I added the following skeleton layers under the vol of the segmentation layer above my codes. However, how should I write the skeleton's info file

swc_file= 'sample.swc'
raw_file = open(swc_file ,'r')
swc_text = raw_file.read()

skel = Skeleton.from_swc(swc_text)
skel.id = 1
vol.skeleton.upload(skel)

examples of my demo.swc:
the swc format

0 0 290.0 10.0 5.0 1.0 -1
1 0 10.0 290.0 3.0 1.0 -1
2 6 5.0 1110.0 5.0 1.0 -1
3 6 5.0 1110.0 6.0 1.0 -1
4 0 880.0 690.0 112.0 1.0 -1
5 0 867.0 1205.0 112.0 1.0 -1
6 0 668.0 1240.0 112.0 1.0 -1
7 6 10.0 90.0 109.0 1.0 -1
8 0 10.0 70.0 111.0 1.0 -1
9 0 10.0 70.0 113.0 1.0 -1
...

The file structure of the usr/home/demo directory is as follows
-4_4_40
-info
-skeletons
--1
when I tried add skeletons in neuroglancer, it reported usr/home/demo/skeletons/info resulted in HTTP error 404:Not found

from neuroglancer.