async removeExpiredPendingRequest(pendingRequests, pendingRequestTTLLimit){
    if(pendingRequestTTLLimit === NO_PENDING_REQUEST_TTL)
      return pendingRequests

    const now = new Date().getTime();
    //TODO:: change seconds to hours
    return _.remove(pendingRequests, (pendingRequest) => {
      const addedTimePlusTtlInterval = new Date(pendingRequest.added_at + pendingRequestTTLLimit * 1000);
      return now < addedTimePlusTtlInterval;
    });
  }

this.removeExpiredPendingRequest(pendingRequests, this.friendsConfig.pending_request_ttl_hours);