Support for lists of lists in the dev playground

I tried the following list example [1], taken from the 1.1 spec in the 
JSON-LD 1.1 dev playground [2]

{
   "@context": {
     "@vocab": "https://purl.org/geojson/vocab#",
     "type": "@type",
     "bbox": {"@container": "@list"},
     "coordinates": {"@container": "@list"}
   },
   "type": "Feature",
   "bbox": [-10.0, -10.0, 10.0, 10.0],
   "geometry": {
     "type": "Polygon",
     "coordinates": [
         [
             [-10.0, -10.0],
             [10.0, -10.0],
             [10.0, 10.0],
             [-10.0, -10.0]
         ]
     ]
   }
   //...
}

However, it returned an error, "jsonld.SyntaxError: Invalid JSON-LD 
syntax; lists of lists are not permitted." Is this part of the spec not 
yet supported by the dev playground?Are there any processors that 
support this feature?

Thanks,

Monika

[1]https://w3c.github.io/json-ld-syntax/#lists

[2]https://json-ld.org/playground-dev/