* @return the ValueConverter for SqlExpressionBuilder that converts Values
* according to the previously set Converters.
*/
protected ValueConverter createExpressionBuilderConverter() {
ConverterManager manager = new ConverterManager();
manager.addGlobalConverter(new DummyConverter());
Iterator i = this.valueConverters.keySet().iterator();
while (i.hasNext()) {
String valueName = (String) i.next();
Converter converter = (Converter) this.valueConverters