title: Use groovy expression for limited IP in mule
body: <p>I created a proxy service with cxf in mule. My version of mule is 3.3.0 CE. Now, I want to put a restriction in my wsdl that created with proxy service.
  My restriction shouldn't allow to per IP that they see my wsdl.
  for this, I find Groovy expression and bellow code:</p>
  
  <pre><code>&lt;expression-filter
          expression="#[groovy:'${allowed}'.contains(message.getInboundProperty('MULE_REMOTE_CLIENT_ADDRESS').substring(message.getInboundProperty('MULE_REMOTE_CLIENT_ADDRESS').indexOf('/')+1, message.getInboundProperty('MULE_REMOTE_CLIENT_ADDRESS').indexOf(':')))]"
          doc:name="Expression" /&gt;
  </code></pre>
  
  <p>I don't know Is good code Or no?
  and I don't know where do I should define my valid Ip?</p>