def format(options)
      options.map do |key, value|
        [{
          format: :f,
          size: :s,
          length: :hls_time,
        }[key] || key, value].map(&:to_s).join('=')
      end
    end
def format(options)
      options.map do |key, value|
        [{
          format: :f,
          size: :s,
          length: :hls_time,
        }[key] || key, value].map(&:to_s).join('=')
      end
    end
Formats keys to melt arguments