class ActionDispatch::Http::Headers

def [](header_name) 

def [](header_name)
  if include?(header_name)
    super
  else
    super(env_name(header_name))
  end
end

def env_name(header_name)

Converts a HTTP header name to an environment variable name. 
def env_name(header_name)
  "HTTP_#{header_name.upcase.gsub(/-/, '_')}"
end

def initialize(*args) 

def initialize(*args)
  if args.size == 1 && args[0].is_a?(Hash)
    super()
    update(args[0])
  else
    super
  end
end