Reads the server-owned classification off a descriptor. _meta is canonical;
annotations is read as the alternate carrier (see the module doc). Returns
undefined — never a partially-invented default — when the server said
nothing, so the caller can tell "unclassified" apart from "classified into a
family I do not approve".
Reads the server-owned classification off a descriptor.
_metais canonical;annotationsis read as the alternate carrier (see the module doc). Returnsundefined— never a partially-invented default — when the server said nothing, so the caller can tell "unclassified" apart from "classified into a family I do not approve".