public interface EntityManager {
    public void persist(Object entity);
    public <T> T merge(T entity);
    public void remove(Object entity);
    public <T> T find(Class<T> entityClass, Object primaryKey);
    public <T> T getReference(Class<T> entityClass, Object primaryKey);
    public void flush();
    public void setFlushMode(FlushModeType flushMode);
    public FlushModeType getFlushMode();
    public void lock(Object entity, LockModeType lockMode);
    public void refresh(Object entity);
    public void clear();
    public boolean contains(Object entity);
    public Query createQuery(String ejbqlString);
    public Query createNamedQuery(String name);
    public Query createNativeQuery(String sqlString);
    public Query createNativeQuery(String sqlString, Class resultClass);
    public Query createNativeQuery(String sqlString, String resultSetMapping);
    public void close();
    public boolean isOpen();
    public EntityTransaction getTransaction();
  }