code: func (o *UUID) setRFC4122Version(version Version) {
  	o[versionIndex] &= 0x0f
  	o[versionIndex] |= uint8(version << 4)
  	o[variantIndex] &= variantSet
  	o[variantIndex] |= VariantRFC4122
  }
docs: // Set the three most significant bits (bits 0, 1 and 2) of the
  // sequenceHiAndVariant equivalent in the array to ReservedRFC4122.