show static method
Implementation
static void show({BuildContext? context, WidgetBuilder? customLoader}) {
if (_isShowing) return;
final OverlayState? overlayState = (context != null ? Overlay.of(context) : navigatorKey.currentState?.overlay);
if (overlayState == null) return;
_overlayEntry = OverlayEntry(
builder: (BuildContext _) => _LoadingOverlay(customLoader: customLoader ?? _customLoaderBuilder),
);
overlayState.insert(_overlayEntry!);
_isShowing = true;
}