NewPluginInitializer constructs new instance of PluginInitializer TODO: switch these parameters to use the builder pattern or just make them all public, this construction method is pointless boilerplate.

ServiceResolver knows how to convert a service reference into an actual location.

WantsAuthorizer defines a function which sets Authorizer for admission plugins that need it.

WantsClientCert defines a fuction that accepts a cert & key for admission plugins that need to make calls and prove their identity.

WantsCloudConfig defines a function which sets CloudConfig for admission plugins that need it.

WantsExternalKubeClientSet defines a function which sets ClientSet for admission plugins that need it.

WantsInternalKubeClientSet defines a function which sets ClientSet for admission plugins that need it.

WantsInternalKubeInformerFactory defines a function which sets InformerFactory for admission plugins that need it.

WantsProxyTransport defines a fuction that accepts a proxy transport for admission plugins that need to make calls to pods.

WantsQuotaRegistry defines a function which sets quota registry for admission plugins that need it.

WantsRESTMapper defines a function which sets RESTMapper for admission plugins that need it.

WantsServiceResolver defines a fuction that accepts a ServiceResolver for admission plugins that need to make calls to services.