code: private void trackNestedMapping(OngoingMappings ongoingMappings) {
          for (ResourceModelMetaData metaData : ongoingMappings.getMetaData()) {
              metaData.getStatistics().countSubsequentMapping();
          }
      }
docs: Record a subsequent mapping in the {@link io.neba.core.resourcemodels.metadata.ResourceModelStatistics statistics}
  of every {@link ResourceModelMetaData resource model} in the current mapping stack.