+ /**
+ * Lookup {@link IdentityRuntimeType} by its QNamme.
+ *
+ * @param qname Identity name
+ * @return {@link IdentityRuntimeType} or {@code null}
+ * @throws NullPointerException if {@code qname} is {@code null}
+ */
+ @Nullable IdentityRuntimeType identityChild(@NonNull QName qname);