code: private void unmapRuleFromAllDataProviders(final R rule) {
          if (rule != null) {
              for (final List<R> mappedRules : dataProvidersToRules.values()) {
                  mappedRules.remove(rule);
              }
          }
      }
docs: Disconnects the specified rule from all data providers.
  
  @param rule Rule to be unmapped.