module ActionDispatch::Response::Setup

def initialize(status = 200, header = {}, body = [])
  @writer = lambda { |x| @body << x }
  @block = nil
  @length = 0
  @status, @header = status, header
  self.body = body
  @cookie = []
  @sending_file = false
  @blank = false
  if content_type = self["Content-Type"]
    type, charset = content_type.split(/;\s*charset=/)
    @content_type = Mime::Type.lookup(type)
    @charset = charset || "UTF-8"
  end
  yield self if block_given?
end