public ReadOnlyCollection <ISignatureHelpSession> GetSessions(ITextView textView) { FrugalList <ISignatureHelpSession> tempSessionList = new FrugalList <ISignatureHelpSession>(); IIntellisenseSessionStack sessionStack = this.IntellisenseSessionStackMap.GetStackForTextView(textView); if (sessionStack == null) { return(tempSessionList.AsReadOnly()); } foreach (var session in sessionStack.Sessions) { ISignatureHelpSession sigHelpSession = session as ISignatureHelpSession; if (sigHelpSession != null) { tempSessionList.Add(sigHelpSession); } } return(tempSessionList.AsReadOnly()); }