code: func (id *ULID) SetTime(ms uint64) error {
  	if ms > maxTime {
  		return ErrBigTime
  	}
  
  	(*id)[0] = byte(ms >> 40)
  	(*id)[1] = byte(ms >> 32)
  	(*id)[2] = byte(ms >> 24)
  	(*id)[3] = byte(ms >> 16)
  	(*id)[4] = byte(ms >> 8)
  	(*id)[5] = byte(ms)
  
  	return nil
  }
docs: // SetTime sets the time component of the ULID to the given Unix time
  // in milliseconds.