class Faker::Address

def zip_code(state_abbreviation: '')
  if state_abbreviation.empty?
    letterified_string = letterify(fetch('address.postcode'))
    return numerify(letterified_string, leading_zero: true)
  end
  # provide a zip code that may be valid for the state provided
  # note: zip code may appear in the correct format for the state provided but may not be an actual state zip.
  bothify(fetch("address.postcode_by_state.#{state_abbreviation}"))
end