@Override
  protected PendingPeerRequest sendRequest() {
    return sendRequestToPeer(
        peer -> {
          LOG.atTrace()
              .setMessage("Requesting {} headers (hash {}...) from peer {}")
              .addArgument(count)
              .addArgument(referenceHash.slice(0, 6))
              .addArgument(peer::getLoggableId)
              .log();
          return peer.getHeadersByHash(referenceHash, count, skip, reverse);
        },
        minimumRequiredBlockNumber);
  }
Retrieves a sequence of headers from a peer.
ethereum/eth/src/main/java/org/hyperledger/besu/ethereum/eth/manager/task/GetHeadersFromPeerByHashTask.java