fer to that
 <a href="NamedSubgraph.html" title="annotation interface in jakarta.persistence"><code>NamedSubgraph</code></a> definition.
 If the target type has inheritance, multiple subgraphs can
 be specified. These additional subgraphs are intended to add
 subclass-specific attributes. Superclass subgraph entries will
 be merged into subclass subgraphs.  

 <p> The value of this element is the name of the subgraph as
 specified by the <code>name</code> element of the corresponding
 <code>NamedSubgraph</c