> objects each of which 
 represents a unique resource manager.

 The resource adapter may return null if it does not implement the 
 <code>XAResource</code> interface. Otherwise, it must return an array 
 of <code>XAResource</code> objects, each of which represents a unique 
 resource manager that was used by the endpoint applications. 
 
 The application server uses the <code>XAResource</code> objects to 
 query each resource manager for a list of in-doubt transactions.
 It then completes each pending tra