if(bytes_amount != nullptr) {
for (int i = 0; i < host_nb; i++) {
for (int j = 0; j < host_nb; j++) {
if (bytes_amount[i * host_nb + j] > 0.0) {
std::vector<LinkImpl*> route;
if(bytes_amount != nullptr) {
for (int i = 0; i < host_nb; i++) {
for (int j = 0; j < host_nb; j++) {
if (bytes_amount[i * host_nb + j] > 0.0) {
std::vector<LinkImpl*> route;