1.```bpf_probe_read(&path, sizeof(path), (void *)addr)```: Now the string ```addr``` points to into our ```path``` variable.
1.```u = USDT(pid=int(pid))```: Initialize USDT tracing for the given PID.
1.```u.enable_probe(probe="http__server__request", fn_name="do_trace")```: Attach our ```do_trace()``` BPF C function to the Node.js ```http__server__request``` USDT probe.
1.```b = BPF(text=bpf_text, usdt=u)```: Need to pass in our USDT object, ```u```, to BPF object creation.
1.```b = BPF(text=bpf_text, usdt_contexts=[u])```: Need to pass in our USDT object, ```u```, to BPF object creation.