module Roda::RodaPlugins::NotAllowed::RequestMethods

def is(*args)

response in that case.
request method must not be allowed, so return a 405
since there was already a successful terminal match, the
that the verb calls inside the block did not match, and
verb calls inside the block, but the block returned, assume
Keep track of verb calls inside the block. If there are any 
def is(*args)
  super(*args) do
    begin
      is_verbs = @_is_verbs = []
      ret = if args.empty?
        yield
      else
        yield(*captures)
      end
      unless is_verbs.empty?
        method_not_allowed(is_verbs.join(', '))
      end
      ret
    ensure
      @_is_verbs = nil
    end
  end
end

def method_not_allowed(verbs)

to the given string of allowed request methods.
Set the response status to 405 (Method Not Allowed), and set the Allow header 
def method_not_allowed(verbs)
  res = response
  res.status = 405
  res['Allow'] = verbs
  nil
end

def root

response for non-GET requests.
Treat +r.root+ similar to r.get '', using a 405 
def root
  super
  if @remaining_path == "/"  && !is_get?
    always{method_not_allowed("GET")}
  end
end