attach static method
Attaches the given Context making it the active Context for the current
Zone and all child Zones and returns a ContextToken
that must be used
to detach the Context.
When a Context is attached, it becomes active and overrides any Context that may otherwise be visible within that Zone. The Context will not be visible to any parent or sibling Zone. The Context will only be visible for the current Zone and any child Zone.
Implementation
@experimental
static ContextToken attach(Context context, [Zone? zone]) {
final entry = ContextStackEntry(context);
_stacks.update(zone ?? Zone.current, (stack) => stack..add(entry),
ifAbsent: () => [entry]);
return entry.token;
}