Add documentation and unit tests

pkg/cloudprovider/providers/azure/azure_test.go

@@ -32,6 +32,7 @@ import (
 	"k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/types"
+	"k8s.io/apimachinery/pkg/util/sets"
 	serviceapi "k8s.io/kubernetes/pkg/api/v1/service"
 	"k8s.io/kubernetes/pkg/cloudprovider/providers/azure/auth"
 	kubeletapis "k8s.io/kubernetes/pkg/kubelet/apis"
@@ -953,6 +954,8 @@ func getTestCloud() (az *Cloud) {
 			MaximumLoadBalancerRuleCount: 250,
 			VMType: vmTypeStandard,
 		},
+		nodeZones:          map[string]sets.String{},
+		nodeInformerSynced: func() bool { return true },
 	}
 	az.DisksClient = newFakeDisksClient()
 	az.InterfacesClient = newFakeAzureInterfacesClient()