} else if (childForm instanceof SlurForm) {
SlurForm contentForm = (SlurForm) childForm;
Slur contentNode = (Slur) contentForm.getMeiNode();
return contentNode;
} else if (childForm instanceof FermataForm) {
FermataForm contentForm = (FermataForm) childForm;
Fermata contentNode = (Fermata) contentForm.getMeiNode();
return contentNode;
} else {
// write back a node of a currently unknown type
UnknownMeiNodeForm contentForm = (UnknownMeiNodeForm) childForm;
return contentForm.getMeiNode();
}
}