code: @Override
  	public Collection<Node> check(final Collection<Node> nodes) {
  		Assert.notNull(nodes, "nodes is null!");
  		this.nodes = nodes;
  
  		this.result = new LinkedHashSet<Node>();
  
          String value = specifier.getValue();
          for (Node node : nodes) {
          	String content = helper.getValue(node);
          	if (content!=null && content.contains(value)) {
          		result.add(node);
          	}
          }
          
          return this.result;
  	}
docs: {@inheritDoc}