PROPlugInRegistering Declarationprotocol PROPlugInRegistering : NSObjectProtocol TopicsInstance MethodsregisteredPlugInGroups()registeredPlugIns()requestedProtocols()shouldLoadFirstInstanceOfPlugIn()Type MethodssharedInstance() RelationshipsInherits FromNSObjectProtocol See AlsoProtocolsFxXPCProtocolPROAPIAccessingPROAPIObjectPROXPCProtocol