code: public static IQProvider<IQ> getIQProvider(String elementName, String namespace) {
          String key = getKey(elementName, namespace);
          return iqProviders.get(key);
      }
docs: Returns the IQ provider registered to the specified XML element name and namespace.
  For example, if a provider was registered to the element name "query" and the
  namespace "jabber:iq:time", then the following stanza would trigger the provider:
  
  <pre>
  &lt;iq type='result' to='joe@example.com' from='mary@example.com' id='time_1'&gt;
  &lt;query xmlns='jabber:iq:time'&gt;
  &lt;utc&gt;20020910T17:58:35&lt;/utc&gt;
  &lt;tz&gt;MDT&lt;/tz&gt;
  &lt;display&gt;Tue Sep 10 12:58:35 2002&lt;/display&gt;
  &lt;/query&gt;
  &lt;/iq&gt;</pre>
  
  <p>Note: this method is generally only called by the internal Smack classes.
  
  @param elementName the XML element name.
  @param namespace the XML namespace.
  @return the IQ provider.