code: public void addEntity(String alias, Class<?> entityClass) {
      EntityType entityType = Model.getType(entityClass);
      if (null == entityType) { throw new RuntimeException("cannot find entity type for " + entityClass); }
      entityTypes.put(alias, entityType);
    }
docs: <p>
  addEntity.
  </p>
  
  @param alias a {@link java.lang.String} object.
  @param entityClass a {@link java.lang.Class} object.