default void writeLong(final long l) {
    final MutableBytes v = MutableBytes.create(8);
    v.setLong(0, l);
    writeBytes(v);
  }
Writes a 8-bytes value.

<p>Note that this is not a "scalar" write: the value will be encoded with exactly 8 bytes.

@param l The 8-bytes long to write.
ethereum/rlp/src/main/java/org/hyperledger/besu/ethereum/rlp/RLPOutput.java