ng_package_data
item = ng_package_data(m, NG_NOFLAGS);
item = ng_package_data(m, NG_NOFLAGS);
item_p ng_package_data(struct mbuf *m, int flags);
if ((_item = ng_package_data((m), flags))) { \
item = ng_package_data(m, NG_NOFLAGS);
if ((item = ng_package_data(m, NG_NOFLAGS)) != NULL) {
item = ng_package_data(m2, NG_NOFLAGS);
item = ng_package_data(m, NG_WAITOK);
item = ng_package_data(NULL, NG_WAITOK);