intridea/rack-stream — pull request #5 by exAspArk (2014-06-18 09:04:40+00:00)
Title: Don't modify headers hash in `open!` method

E.g. in case if I have a frozen hash it shows me an error: "can't modify frozen Hash (RuntimeError)"

```ruby
class EventHandler
include Rack::Stream::DSL

STATUS = 200
HEADERS = {
'Content-Type' => 'text/event-stream; charset=UTF-8',
'Connection' => 'keepalive',
'Cache-Control' => 'no-cache, no-store'
}

stream do
...
[STATUS, HEADERS, []]
end
end
```