public static async Task <NIType> GetTypeDiagramSignatureAsync(this Envoy typeDiagramEnvoy) { IProvideDataType typeDiagramCacheService = typeDiagramEnvoy.GetBasicCacheServices() .OfType <IProvideDataType>() .FirstOrDefault(); if (typeDiagramCacheService != null) { return(await typeDiagramCacheService.GetDataTypeAsync()); } return(NIType.Unset); }