title: TypeError: wrong argument type class (expected module) in rspec
body: <p>i'm developing a simple net application (packed as a gem) to learn Ruby and TDD.
  I have this class (receiver.rb):</p>
  
  <pre><code>require 'eventmachine'
  class Receiver &lt; EM::Connection
      def initialize(port)
          EM.run do
              EM.open_datagram_socket('0.0.0.0', port, self)
          end
      end
  end
  </code></pre>
  
  <p>And this test (receiver_spec.rb):</p>
  
  <pre><code>require "spec_helper"
  require "net/receiver"
  
  describe "Receiver" do
      it "can istantiate" do
          @rec = Receiver.new(500)
      end
  end
  </code></pre>
  
  <p>Anyway, when i run <code>rspec</code> it prints out this:</p>
  
  <pre><code>1) Receiver can istantiate
       Failure/Error: @rec = Receiver.new(500)
       TypeError:
         wrong argument type Receiver (expected Module)
       # /var/lib/gems/1.9.1/gems/eventmachine-     1.0.7/lib/eventmachine.rb:1535:in `include'
       # /var/lib/gems/1.9.1/gems/eventmachine-1.0.7/lib/eventmachine.rb:1535:in `block in klass_from_handler'
       # /var/lib/gems/1.9.1/gems/eventmachine-1.0.7/lib/eventmachine.rb:1535:in `initialize'
       # /var/lib/gems/1.9.1/gems/eventmachine-1.0.7/lib/eventmachine.rb:1535:in `new'
       # /var/lib/gems/1.9.1/gems/eventmachine-1.0.7/lib/eventmachine.rb:1535:in `klass_from_handler'
       # /var/lib/gems/1.9.1/gems/eventmachine- 1.0.7/lib/eventmachine.rb:867:in `open_datagram_socket'
       # ./lib/rppc/net/receiver.rb:9:in `block in initialize'
       # /var/lib/gems/1.9.1/gems/eventmachine-1.0.7/lib/eventmachine.rb:187:in `call'
       # /var/lib/gems/1.9.1/gems/eventmachine-1.0.7/lib/eventmachine.rb:187:in `run_machine'
       # /var/lib/gems/1.9.1/gems/eventmachine-1.0.7/lib/eventmachine.rb:187:in `run'
       # ./lib/rppc/net/receiver.rb:8:in `initialize'
       # ./spec/net/receiver_spec.rb:6:in `new'
       # ./spec/net/receiver_spec.rb:6:in `block (2 levels) in &lt;top (required)&gt;'
  </code></pre>
  
  <p>I'm quite new to the ruby environment, so if i missed something let me know.</p>