About the etag in `fetchUserEvents`

[Tangdixi]

Sorry to bother you again @onmyway133 😓
This method is return an Observable<[Events]> (transform from Observable<Response>)

  public func fetchUserEvents(etag: String? = nil,
                              offset: Int = 0, perPage: Int = Constant.defaultPerPage) -> Observable<[Event]> {
    if !isAuthenticated {
      return Observable<[Event]>.error(Error.authenticationRequiredError())
    }

    let requestDescriptor: RequestDescriptor = construct {
      $0.path = "users/\(user?.login ?? "")/received_events"
      $0.offset = offset
      $0.perPage = perPage
      $0.etag = etag
    }

    return enqueue(requestDescriptor).map {
      return Parser.all($0)
    }
  }

So how can I fetch the etag .....

[onmyway133]

@Tangdixi Hi, no problem. I'm here to help 😄

What do you mean by "fetch the etag"?

[Tangdixi]

Just like this scene:
I perform a fetchUserEvents request when I run my App at the first time.
Here, I suppose I need to store the etag from the Response and use it in fetchUserEvents next time, right?
I dig deep into the source code, found the etag is defined in Response.swift:

public class Response {

  // .....

  // The etag uniquely identifying this response data.
  public var etag: String {
    return urlResponse.allHeaderFields["ETag"] as? String ?? ""
  }

  // .....
}

But the fetchUserEvents method is return a Observable<[Event]>, not a Observable<Response>. So I can't find a way to get the etag ...