module Rack::Utils

def best_q_match(q_value_header, available_mimes)

is arbitrary.
matches (same specificity and quality), the value returned
in RFC 2616 Section 14. If there are multiple best
Return best accept value to use, based on the algorithm 
def best_q_match(q_value_header, available_mimes)
  values = q_values(q_value_header)
  matches = values.map do |req_mime, quality|
    match = available_mimes.find { |am| Rack::Mime.match?(am, req_mime) }
    next unless match
    [match, quality]
  end.compact.sort_by do |match, quality|
    (match.split('/', 2).count('*') * -10) + quality
  end.last
  matches&.first
end