code: protected Interceptor ensureInterceptor( String n )
      {
          Interceptor i = null;
          if ( _interceptors == null )
          {
              _interceptors = new HashMap<String,Interceptor>();
          }
          else
          {
              i = _interceptors.get( n );
          }
  
          if ( i == null )
          {
              try
              {
                  i  = (Interceptor) getControlService( getControlBeanContext().getClassLoader().loadClass( n ), null );
              }
              catch ( Exception e )
              {
                  // Couldn't instantiate the desired service; usually this is because the service interface itself
                  // isn't present on this system at runtime (ClassNotFoundException), or if the container of the
                  // control didn't registers the service.
  
                  /* TODO log a message here to that effect, but just swallow the exception for now. */
              }
              finally
              {
                  // We want to always return an interceptor, so if we can't get the one we want, we'll substitute
                  // a "null" interceptor that does nothing.
                  if ( i == null)
                      i = new NullInterceptor();
  
                  _interceptors.put( n, i );
              }
          }
          return i;
      }
docs: Retrieves interceptor instances, creates them lazily.