/**
  * {@inheritDoc}
  *
  * @param child
  * @return
  * @see org.picocontainer.MutablePicoContainer#addChildContainer(org.picocontainer.PicoContainer)
  */
 public MutablePicoContainer addChildContainer(final PicoContainer child) {
   if (logger.isDebugEnabled()) {
     logger.debug("Adding child container: " + child + " to container " + delegate);
   }
   return delegate.addChildContainer(child);
 }