void addOperation(OID oid, DML dml) { String key = oid + ":" + dml.getTable().getName();
void addOperation(Object obj, DML dml) { Object key = new CompoundKey(obj, dml.getTable());
    void addOperation(OID oid, DML dml) {        String key = oid + ":" + dml.getTable().getName();        if (dml instanceof Delete) {            DML prev = (DML) m_operationMap.get(key);            if (prev != null) {                m_operations.remove(prev);            }        }        m_operationMap.put(key, dml);        m_operations.add(dml);    }