class Authenticate < Header
  attr_accessor :scheme, :realm, :domain, :nonce, :opaque, :stale, :algorithm,
  :qop

  def initialize
    @name = "Authenticate"
    super
  end

  def assign(val_str, parse=true)
    unless parse
      cache_and_clear(val_str, [:realm, :domain, :nonce, :opaque, :stale, :algorithm, :qop])
    else
      @frozen_str = nil
      @scheme, challenge = val_str.split(" ", 2)
      challenge.split(",").each do |x|
        k, v = x.split("=", 2)
        self.send((k.strip+"=").to_sym, v.strip)
      end
      @header_params = {}

    end  # parse or assign
    self
  end    # assign method
end

class  WwwAuthenticate < Authenticate
  def initialize
    @name = "WWW-Authenticate"
    super
  end
end

auth = SipHeaders::WwwAuthenticate.new
puts "1"
auth.assign challenge #challenge is a previously set string
# I've also tried this: auth = SipHeaders::Authenticate.assign challenge
puts "2"