func NewGetBlockHeadersReqHandler(pm p2pcommon.PeerManager, peer p2pcommon.RemotePeer, logger *log.Logger, actor p2pcommon.ActorService) *getBlockHeadersRequestHandler {
    bh := &getBlockHeadersRequestHandler{BaseMsgHandler{protocol: p2pcommon.GetBlockHeadersRequest, pm: pm, peer: peer, actor: actor, logger: logger}, newAsyncHelper()}
    return bh
}