debugUnbindWidget method
void
debugUnbindWidget()
Releases the binding established by debugBindWidget. Called by
SectionedSliverListState during dispose and before a controller
swap.
Implementation
void debugUnbindWidget() {
assert(
_bindingCount > 0,
"SectionedListController binding count would go negative. "
"debugUnbindWidget called more times than debugBindWidget.",
);
_bindingCount--;
}