code: public Set<String> resourceNames(final String catalog) {
  		Set<String> resources = new HashSet<>();
  		for (ResourceSelection selection : selections) {
  			if (selection.getCatalog().equals(catalog)) {
  				resources.add(selection.getName());
  			}
  		}
  		return resources;
  	}
docs: 根据类别名称获取集合中包含的同一类别的资源名称。
  
  @param catalog
  类别
  @return 资源名称集合