docs: Xid[] getPreparedXids() {
  
          Iterator it = resources.keySet().iterator();
          Xid      curXid;
          HashSet  preparedSet = new HashSet();
  
          while (it.hasNext()) {
              curXid = (Xid) it.next();
  
              if (((JDBCXAResource) resources.get(curXid)).state
                      == JDBCXAResource.XA_STATE_PREPARED) {
                  preparedSet.add(curXid);
              }
          }
  
          return (Xid[]) preparedSet.toArray(new Xid[0]);
      }