// the 1.x datatypes
supportedDatatypes.put(BooleanAttribute.identifier, new BooleanAttributeProxy());
supportedDatatypes.put(StringAttribute.identifier, new StringAttributeProxy());
supportedDatatypes.put(DateAttribute.identifier, new DateAttributeProxy());
supportedDatatypes.put(TimeAttribute.identifier, new TimeAttributeProxy());
supportedDatatypes.put(DateTimeAttribute.identifier, new DateTimeAttributeProxy());
supportedDatatypes.put(DayTimeDurationAttribute.identifier,
new DayTimeDurationAttributeProxy());
supportedDatatypes.put(YearMonthDurationAttribute.identifier,
new YearMonthDurationAttributeProxy());
supportedDatatypes.put(DoubleAttribute.identifier, new DoubleAttributeProxy());