code: @SuppressWarnings("unchecked")
      public ConfigProperty getConfigProperty(final String groupName, final String propertyName) {
          final Query query = pm.newQuery(ConfigProperty.class, "groupName == :groupName && propertyName == :propertyName");
          final List<ConfigProperty> result = (List<ConfigProperty>) query.execute(groupName, propertyName);
          return Collections.isEmpty(result) ? null : result.get(0);
      }
docs: Returns a ConfigProperty with the specified groupName and propertyName.
  @param groupName the group name of the config property
  @param propertyName the name of the property
  @return a ConfigProperty object
  @since 1.3.0