public BlockHeaderBuilder populateFrom(final ProcessableBlockHeader processableBlockHeader) {
    checkNotNull(processableBlockHeader);
    parentHash(processableBlockHeader.getParentHash());
    coinbase(processableBlockHeader.getCoinbase());
    difficulty(processableBlockHeader.getDifficulty());
    number(processableBlockHeader.getNumber());
    gasLimit(processableBlockHeader.getGasLimit());
    timestamp(processableBlockHeader.getTimestamp());
    baseFee(processableBlockHeader.getBaseFee().orElse(null));
    processableBlockHeader.getPrevRandao().ifPresent(this::prevRandao);
    processableBlockHeader.getParentBeaconBlockRoot().ifPresent(this::parentBeaconBlockRoot);
    return this;
  }
A utility class for building block headers.
ethereum/core/src/main/java/org/hyperledger/besu/ethereum/core/BlockHeaderBuilder.java