Collision-free unique key for a group path: the JSON encoding of the label
array. A plain label join would be ambiguous whenever a model-derived label
contains the join separator, silently merging distinct groups' expansion /
render identity downstream.
Collision-free unique key for a group path: the JSON encoding of the label array. A plain label join would be ambiguous whenever a model-derived label contains the join separator, silently merging distinct groups' expansion / render identity downstream.