class RuboCop::Cop::Style::FormatStringToken

def on_str(node)
  return if placeholder_argument?(node)
  return if node.each_ancestor(:xstr, :regexp).any?
  tokens(node) do |detected_style, token_range|
    if detected_style == style ||
       unannotated_format?(node, detected_style)
      correct_style_detected
    else
      style_detected(detected_style)
      add_offense(node, location: token_range,
                        message: message(detected_style))
    end
  end
end