This class implements an event sink for a particular RCW. Unlike the implementation of events in TlbImp'd assemblies, we will create only one event sink per RCW (theoretically RCW might have several ComEventSink evenk sinks - but all these implement different source intefaces). Each ComEventSink contains a list of ComEventSinkMethod objects - which represent a single method on the source interface an a multicast delegate to redirect the calls. Notice that we are chaining multicast delegates so that same ComEventSinkMedhod can invoke multiple event handlers). ComEventSink implements an IDisposable pattern to Unadvise from the connection point. Typically, when RCW is finalized the corresponding Dispose will be triggered by ComEventSinksContainer finalizer. Notice that lifetime of ComEventSinksContainer is bound to the lifetime of the RCW.