private CompletableFuture<Block> retrieveNonAnnouncedBlock(final long blockNumber) {
    LOG.trace("Retrieve non announced block {} from peers", blockNumber);
    return getBlockFromPeers(Optional.empty(), blockNumber, Optional.empty());
  }
Process pending Children if any

@param block the block to process the children
@return true if block has any pending child
ethereum/eth/src/main/java/org/hyperledger/besu/ethereum/eth/sync/BlockPropagationManager.java