fromJson static method
Absent or unrecognised reads as ltr — a server predating this field,
or one whose override didn't survive normalisation, gets today's
behaviour rather than a thrown error. The server already normalises
direction to ltr/rtl; the client does not trust that it did.
Implementation
static PanelDirection fromJson(Object? value) =>
value == 'rtl' ? PanelDirection.rtl : PanelDirection.ltr;