test - unit - network - get providerProxy via public method

test/unit/network-contoller-test.js

@@ -33,11 +33,12 @@ describe('# Network Controller', function () {
 
   describe('network', function () {
     describe('#provider', function () {
-      it('provider should be updatable without reassignment', function () {
+      it.only('provider should be updatable without reassignment', function () {
         networkController.initializeProvider(networkControllerProviderConfig)
-        const proxy = networkController._proxy
-        proxy.setTarget({ test: true, on: () => {} })
-        assert.ok(proxy.test)
+        const providerProxy = networkController.getProviderAndBlockTracker().provider
+        assert.equal(providerProxy.test, undefined)
+        providerProxy.setTarget({ test: true })
+        assert.equal(providerProxy.test, true)
       })
     })
     describe('#getNetworkState', function () {