code: def add(key, value):
          
          tr = TrackedRequest.instance()
          tr.tag(key, value)
docs: Adds context to the currently executing request.
  
          :key: Any String identifying the request context.
                Example: "user_ip", "plan", "alert_count"
          :value: Any json-serializable type.
                Example: "1.1.1.1", "free", 100
          :returns: nothing.