Lack of support for positional references

[jpromers]

Support is necessary for positional references...

`
polyline":{
...
"arcType":"NONE",
"positions":{
"references":[
"Facility/AGI#position","Satellite/ISS#position"
]
}

`
Position constructor doesn't accept "references" attribute. This comes from the CZML simple example from the sandcastle that is the basis for your "simple" example.

[astrojuanlu]

Hi @jpromers , sorry for the delay. PositionList accepts references:

czml3/src/czml3/properties.py

Line 431 in cea9aab

references = attr.ib(default=None)

and Position accepts reference:

czml3/src/czml3/properties.py

Line 230 in cea9aab

reference = attr.ib(default=None)

I think you might be confusing the two. It's not your fault, CZML documentation is quite lacking. Please let me know if we can close this issue.