def prepare!(env)
      @env      = env
      @request  = Rack::Request.new(env)
      @response = Rack::Response.new
      @headers  = @response.header
      @params   = @request.GET.merge(@request.POST)
      @params.default_proc = proc do |hash, key|
        hash[key.to_s] if Symbol === key
      end
    end
def prepare!(env)
      @env      = env
      @request  = Rack::Request.new(env)
      @response = Rack::Response.new
      @headers  = @response.header
      @params   = @request.GET.merge(@request.POST)
      @params.default_proc = proc do |hash, key|
        hash[key.to_s] if Symbol === key
      end
    end
Creates a new Context object.

 @param app the context's application
 Initializes the attributes based on an environment.

 @param env the environment to use