parseColumn method
Parses a bare content tree, with no surrounding nudge surface.
Exposed for the PiP campaign type, whose full-screen region is drawn by
this same renderer but which owns its own presentation — so it needs the
column without a container. Returns null for a missing or empty tree,
matching parse.
Implementation
NudgeColumn? parseColumn(Map<String, dynamic>? layout) {
if (layout == null || layout.isEmpty) return null;
return _column(layout);
}