wherePrimary method
Creates a WidgetSelector that finds all GridView where primary matches the condition.
Example usage:
spot<GridView>().wherePrimary((it) => it.isTrue()).existsOnce();
Implementation
@useResult
WidgetSelector<GridView> wherePrimary(MatchProp<bool> match) {
return withDiagnosticProp<bool>('primary', match);
}