code: def tzabbr_register(abbr, name, region, zone, dst):
    
    newabbr = tzabbr()
    newabbr.abbr = abbr
    newabbr.name = name
    newabbr.region = region
    newabbr.zone = zone
    newabbr.dst = dst
  
    if abbr not in all:
      all[abbr] = newabbr
  
    if not region in regions:
      regions[region] = {}
  
    assert abbr not in regions[region]
    regions[region][abbr] = newabbr
docs: Register a new timezone abbreviation in the global registry.
  
    If another abbreviation with the same name has already been registered it new
    abbreviation will only be registered in region specific dictionary.