Microsoft.VisualStudio.LanguageServices.PdbSourceDocument.AbstractSourceLinkService.LocateSymbolFileAsync(Microsoft.VisualStudio.Debugger.Contracts.SymbolLocator.SymbolLocatorPdbInfo, Microsoft.VisualStudio.Debugger.Contracts.SymbolLocator.SymbolLocatorSearchFlags, System.Threading.CancellationToken)