Microsoft.CodeAnalysis.ChangeNamespace.AbstractChangeNamespaceService<TCompilationUnitSyntax, TMemberDeclarationSyntax, TNamespaceDeclarationSyntax, TNameSyntax, TSimpleNameSyntax, TCrefSyntax>.TryGetApplicableContainerFromSpanAsync(Microsoft.CodeAnalysis.Document, Microsoft.CodeAnalysis.Text.TextSpan, System.Threading.CancellationToken)