Property :: primaryKeyDefinition - Get key definition for primary key

The function returns the type definition for the primary or identifying key for the type definition of the property handle. This is not necessarily a sort key of the collection referenced by the property handle.

For weak-typed collections, the primary key for the property is not necessarily the primary key for the currently selected instance, but the primary key defined for the data type the collection is based on. In order to obtain the primary key definition for the currently selected instance, one may call currentKeyDefinition().