module ActionDispatch::Http::Cache::Response

def cache_control_headers
  cache_control = {}
  cache_control_segments&.each do |segment|
    directive, argument = segment.split("=", 2)
    if SPECIAL_KEYS.include? directive
      directive.tr!("-", "_")
      cache_control[directive.to_sym] = argument || true
    else
      cache_control[:extras] ||= []
      cache_control[:extras] << segment
    end
  end
  cache_control
end