JPA Method
in javax.persistence.Cache

T unwrap(
  Class<T> cls
)


Return an object of the specified type to allow access to the provider-specific API. If the provider's Cache implementation does not support the specified class, the PersistenceException is thrown.
Parameters:
cls - the class of the object to be returned. This is normally either the underlying Cache implementation class or an interface that it implements.
Return:
an instance of the specified class
Throws:
PersistenceException - if the provider does not support the call
Since:
JPA 2.1