for (SourceBindingWrapper sbw : contentForm
.getSourceBindingWrappers()) { // insert the wrapped sources
contentNode.getSources().add(sbw.getSource().getId());
}
if (contentNode.getSources().isEmpty())
contentNode.unsetSources();
contentNode.getMRestsAndKeySigsAndProports().clear();
for (BasicElement contentChildForm : contentForm.getChildren()) {
contentNode.getMRestsAndKeySigsAndProports().add(
handleScoreChild(contentChildForm, saveAllVariants));
}