code: public String getCategoriesAsString() {
  		List<String> categories = getCategories();
  		String categoriesStr = "";
  		if (categories != null && !categories.isEmpty()) {
  			categoriesStr = StringUtils.join(categories.toArray(), CATEGORY_SEPARATOR);
  		}
  
  		return categoriesStr;
  	}
docs: Concatenates the categories as a String separated by
  {@link DescribeService#CATEGORY_SEPARATOR}
  
  @return