connect(signal, SIGNAL(samples_cleared()),
this, SLOT(on_data_cleared()));
connect(signal, SIGNAL(samples_added(uint64_t, uint64_t, uint64_t)),
connect(signal, SIGNAL(samples_cleared()),
this, SLOT(on_data_cleared()));
connect(signal, SIGNAL(samples_added(uint64_t, uint64_t, uint64_t)),