                 facebookConnectError: ErrorEnvelope? = nil,
                 fetchActivitiesResponse: [Activity]? = nil,
                 fetchActivitiesError: ErrorEnvelope? = nil,
+                fetchBackingResponse: Backing = .template,
                 fetchCategoriesResponse: CategoriesEnvelope? = nil,
                 fetchCommentsResponse: [Comment]? = nil,
                 fetchCommentsError: ErrorEnvelope? = nil,

  func fetchBacking(forProject project: Project, forUser user: User)
    -> SignalProducer<Backing, ErrorEnvelope> {

    return SignalProducer(
      value: Backing(
        amount: 10,
        backerId: 1,
        id: 1,
        locationId: 1,
        pledgedAt: 123456789.0,
        projectCountry: "US",
        projectId: 1,
        reward: .template,
        rewardId: 1,
        sequence: 10,
        shippingAmount: 2,
        status: .pledged
      )
    )
  }

  internal func fetchDiscovery(paginationUrl paginationUrl: String)

    ]

    self.fetchActivitiesError = fetchActivitiesError

    self.fetchBackingResponse = fetchBackingResponse

    self.fetchCategoriesResponse = fetchCategoriesResponse ?? (.template
      |> CategoriesEnvelope.lens.categories .~ [
