in src/spark_automerge_wrapper.js [30:42]
function decodeMessage(msg) {
  const metaDataLengthSize = 1, nonZeroPaddingSize = 1;
  const metaDataLength = msg[0];
  const totalSize = msg.length;
  // Decode meta data from msg to JSON
  const metaDataBuf = msg.subarray(metaDataLengthSize, metaDataLengthSize + metaDataLength)
  const metaData = JSON.parse(String.fromCharCode(...metaDataBuf));
  // Decode sync message
  const syncMessage = msg.subarray(metaDataLengthSize + metaDataLength, totalSize - nonZeroPaddingSize);
  return [metaData, syncMessage];
}