class RuboCop::Cop::Style::FormatStringToken

def token_ranges(contents)
  format_string = RuboCop::Cop::Utils::FormatString.new(contents.source)
  format_string.format_sequences.each do |detected_sequence|
    next if detected_sequence.percent?
    token = contents.begin.adjust(begin_pos: detected_sequence.begin_pos,
                                  end_pos: detected_sequence.end_pos)
    yield(detected_sequence, token)
  end
end