private ClassMetadata singleClassConstraint() {
if (requiresSort()) {
return null;
}
QConClass clazzconstr = classConstraint();
if (clazzconstr == null) {
return null;
}
ClassMetadata clazz = clazzconstr._classMetadata;
if (clazz == null) {
return null;
}
if (clazzconstr.hasChildren() || clazz.isArray()) {
return null;
}
return clazz;
}
