final PropertyValue pv = collection.getItem(i);
if (pv.canEvalKeyword()) {
final FoValue foValue = this.convertValueToFoValue(pv);
returnArray[i] = foValue.toXslFo();
} else if (pv instanceof DtName) {
final DtName dtName = (DtName) pv;
returnArray[i] = dtName.getValue();
} else if (pv instanceof DtString) {
final DtString stringDT = (DtString) pv;
returnArray[i] = stringDT.getValue();
} else {
throw this.unexpectedRetrieval();