class Mime::Type

def register(string, symbol, mime_type_synonyms = [], extension_synonyms = [], skip_lookup = false)
  new_mime = Type.new(string, symbol, mime_type_synonyms)
  SET << new_mime
  ([string] + mime_type_synonyms).each { |str| LOOKUP[str] = new_mime } unless skip_lookup
  ([symbol] + extension_synonyms).each { |ext| EXTENSION_LOOKUP[ext.to_s] = new_mime }
  @register_callbacks.each do |callback|
    callback.call(new_mime)
  end
  new_mime
end