code: public Collection<InstanceContextBean> apply( Collection<InstanceContextBean> instances ) {
  
  		final ArrayList<InstanceContextBean> result = new ArrayList<InstanceContextBean> ();
  		for( InstanceContextBean instance : instances ) {
  			boolean installerMatches = this.installerName == null || this.installerName.equalsIgnoreCase( instance.getInstaller());
  			if( installerMatches && this.rootNode.isMatching( instance ))
  				result.add( instance );
  		}
  
  		result.trimToSize();
  		return Collections.unmodifiableCollection(result);
  	}
docs: Applies this filter to the given instances.
  
  @param instances the collection of instances to which this filter has to be applied.
  @return the instances of the provided collection that matches this filter.