code: void writeEntityTypes(Collection<EntityType> entityTypes, XlsxWriter writer) {
      LinkedList<EntityType> sortedEntityTypes = sortEntityTypesAbstractFirst(entityTypes);
      if (!writer.hasSheet(EMX_ENTITIES)) {
        writer.createSheet(EMX_ENTITIES, newArrayList(ENTITIES_ATTRS.keySet()));
      }
      writer.writeRows(sortedEntityTypes.stream().map(EntityTypeMapper::map), EMX_ENTITIES);
    }
docs: package private for test