function getHashSize(versionByte) {
  switch (versionByte & 7) {
  case 0:
    return 160;
  case 1:
    return 192;
  case 2:
    return 224;
  case 3:
    return 256;
  case 4:
    return 320;
  case 5:
    return 384;
  case 6:
    return 448;
  case 7:
    return 512;
  }
}
Retrieves the the length in bits of the encoded hash from its bit
representation within the version byte.

@param {number} versionByte