int gtnets_create_flow(int src, int dst, long datasize, void* metadata);
double gtnets_get_time_to_next_flow_completion();
int gtnets_run_until_next_flow_completion(void*** metadata, int* number_of_flows);
int gtnets_create_flow(int src, int dst, long datasize, void* metadata);
double gtnets_get_time_to_next_flow_completion();
int gtnets_run_until_next_flow_completion(void*** metadata, int* number_of_flows);