private suspend fun getSitePositions(apiRequest: ApiRequest): List<ApiSitePosition> =
        when (val positions = sitePositionsCache[apiRequest.siteId].awaitFirstOrNull()) {
            null -> {
                sitePositionsRequestMutex.withLock {
                    when (val positions = sitePositionsCache[apiRequest.siteId].awaitFirstOrNull()) {
                        null -> {
                            val positions = apiService.getSitePositions(apiRequest)
                            sitePositionsCache.fastPutIfAbsent(apiRequest.siteId, positions)
                            positions
                        }
                        else -> positions
                    }
                }
            }
            else -> positions
        }