int dst_traced = comm->group()->index(dst);
int src_traced = comm->group()->index(src);
instr_extra_data extra = xbt_new0(s_instr_extra_data_t, 1);
int dst_traced = comm->group()->index(dst);
int src_traced = comm->group()->index(src);
instr_extra_data extra = xbt_new0(s_instr_extra_data_t, 1);