code: public static synchronized void bind(String propertiesPath, Class clazz) throws BindingException
      {
          if (em == null)
          {
              em = PersistenceService.getEM(emf, propertiesPath, clazz.getName());
          }
          onBind(clazz);
      }
docs: Bind.
  
  @param propertiesPath
  the properties path
  @param clazz
  the clazz
  @throws BindingException
  the binding exception