String keySubgraph default ""

(Optional) If the attribute references a Map type, this element can be used to specify a subgraph for the Key in the case of an Entity key type. A keySubgraph can not be specified without the Map attribute also being specified. 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.

The value of this element is the name of the key subgraph as specified by the name element of the corresponding NamedSubgraph element. If multiple key subgraphs are specified due to inheritance, they are referenced by this name.