code: function decode5(s) {
    assert.equal(s.length, 5)
    const [ upper, belowUpper, mid, aboveLower, lower ] = s
    return (decode(upper) << 24) | (decode(belowUpper) << 18)
      | (decode(mid) << 12) | (decode(aboveLower) << 6) | decode(lower)
  }
docs: Decodes five chars into an 30 bit number
  
  @name decode5
  
  @param {String} s the chars to decode
  @returns {Number} a 30 bit number