def unify_voiced_katakana!(src)
      halfwidth =
        Characters::HALFWIDTH_VOICED_KATAKANA +
        Characters::HALFWIDTH_SEMI_VOICED_KATAKANA
      fullwidth =
        Characters::VOICED_KATAKANA +
        Characters::SEMI_VOICED_KATAKANA
      halfwidth.zip(fullwidth).inject(src) do |str, (h, f)|
        str.gsub!(h, f) || str
      end
    end
def unify_voiced_katakana!(src)
      halfwidth =
        Characters::HALFWIDTH_VOICED_KATAKANA +
        Characters::HALFWIDTH_SEMI_VOICED_KATAKANA
      fullwidth =
        Characters::VOICED_KATAKANA +
        Characters::SEMI_VOICED_KATAKANA
      halfwidth.zip(fullwidth).inject(src) do |str, (h, f)|
        str.gsub!(h, f) || str
      end
    end
Unify halfwidth (semi) voiced katakana to one fullwidth voiced katakana