Registrar in PluginRegistry has been deprecated in Examples

[aguilita1]

flutter_braintree-4.0.0\android\src\main\java\com\example\flutter_braintree\FlutterBraintreeDropIn.java:11: warning: [deprecation] Registrar in PluginRegistry has been deprecated
import io.flutter.plugin.common.PluginRegistry.Registrar;

flutter_braintree-4.0.0\android\src\main\java\com\example\flutter_braintree\FlutterBraintreePlugin.java:18: warning: [deprecation] Registrar in PluginRegistry has been deprecated
import io.flutter.plugin.common.PluginRegistry.Registrar;

flutter_braintree-4.0.0\android\src\main\java\com\example\flutter_braintree\FlutterBraintreeDropIn.java:40: warning: [deprecation] Registrar in PluginRegistry has been deprecated
public static void registerWith(Registrar registrar) {

flutter_braintree-4.0.0\android\src\main\java\com\example\flutter_braintree\FlutterBraintreePlugin.java:29: warning: [deprecation] Registrar in PluginRegistry has been deprecated
public static void registerWith(Registrar registrar) {