An opaque reference is an object that is bound into the name service
to represent another object. When an object implementing this interface
is retrived from a WLContext (via lookup or listBindings), the naming
service returns the object returned by getReferent().
OpaqueReference is an alternative to javax.naming.Reference. Where
Reference requires the caller to manage producing the referent,
OpaqueReference allows the reference to encapsulate this process.