private ElementSerializer startDoc(
XmlSerializer serializer, Object element, boolean errorOnUnknown, String elementAlias)
throws IOException {
serializer.startDocument(null, null);
SortedSet<String> aliases = new TreeSet<String>();
computeAliases(element, aliases);
if (elementAlias != null) {
aliases.add(elementAlias);
}
for (String alias : aliases) {
String uri = getNamespaceUriForAliasHandlingUnknown(errorOnUnknown, alias);
serializer.setPrefix(alias, uri);
}
return new ElementSerializer(element, errorOnUnknown);
}