How to add custom property to Endpoint?

[SteveCollins]

Hi -- I'm using Swashbuckle.AspNetCore.SwaggerGen with .NET Core 3.1 API project.  We need to assign a custom property (called "x-FilterApplied") to each endpoint (1:1 correspondence with OperationId).  How can this be accomplished?  Please point to documentation and/or examples. 

[SteveCollins]

Nevermind.  We figured it out.  Thanks