default int getCheckPointWindowSize(final BlockHeader blockHeader) {
    return 1;
  }
Depending on the consensus, several block headers must be downloaded before the checkpoint in
order to validate the following blocks. This method returns the necessary number of block
headers to download to be able to start the checkpoint sync

@param blockHeader of the checkpoint
@return number of headers to download
ethereum/core/src/main/java/org/hyperledger/besu/ethereum/core/BlockHeaderFunctions.java