code: private List<Property> getPropertiesForCategory(List<Property> localProperties, String category) {
          List<Property> categoryProperties = new ArrayList<Property>();
          for (Property property : localProperties) {
              if (property.getCategory() != null && property.getCategory().equals(category)) {
                  categoryProperties.add(property);
              }
          }
          return categoryProperties;
      }
docs: Convenience method to get all the properties of one category.