code: @Nonnull
    public EntityManager createEntityManager (@SuppressWarnings ("rawtypes") final Map aMap)
    {
      // Create entity manager (factory may be null - e.g. after close)
      final EntityManager aEntityManager = getEntityManagerFactory ().createEntityManager (aMap);
      if (aEntityManager == null)
        throw new IllegalStateException ("Failed to create EntityManager from factory " +
                                         m_aFactory +
                                         " with parameters " +
                                         aMap +
                                         "!");
      return aEntityManager;
    }
docs: Create a new {@link EntityManager} with custom properties!
  
  @param aMap
  The custom properties to use. May be <code>null</code> for no
  properties.
  @return The created {@link EntityManager} and never <code>null</code>.