code: func ServerBaseContext(baseCtx context.Context, h http.Handler) http.Handler {
  	fn := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
  		ctx := r.Context()
  		baseCtx := baseCtx
  
  		// Copy over default net/http server context keys
  		if v, ok := ctx.Value(http.ServerContextKey).(*http.Server); ok {
  			baseCtx = context.WithValue(baseCtx, http.ServerContextKey, v)
  		}
  		if v, ok := ctx.Value(http.LocalAddrContextKey).(net.Addr); ok {
  			baseCtx = context.WithValue(baseCtx, http.LocalAddrContextKey, v)
  		}
  
  		h.ServeHTTP(w, r.WithContext(baseCtx))
  	})
  	return fn
  }
docs: // ServerBaseContext wraps an http.Handler to set the request context to the
  // `baseCtx`.