class Rack::Head

all other requests unchanged.
Rack::Head returns an empty body for all HEAD requests. It leaves

def call(env) 

def call(env)
  status, headers, body = @app.call(env)
  if env[REQUEST_METHOD] == HEAD
    [
      status, headers, Rack::BodyProxy.new([]) do
        body.close if body.respond_to? :close
      end
    ]
  else
    [status, headers, body]
  end
end

def initialize(app) 

def initialize(app)
  @app = app
end