module IntegerToJapanese
  VERSION: String
  # See the writing guide of rbs: https://github.com/ruby/rbs#guides
  def to_hiragana: -> String?
  def to_katakana: -> String?
  def to_kanji: -> String?
  def digits_map: -> String
  def convert_digit_to_hiragana: -> Array[String|bool]
  def convert_digit_to_kanji: -> Array[String|bool]
  def convert_ten_numerals: -> String
end