let n0 = dsp.oscillator { frequency: 1000, waveform: "sine" };
let n1 = dsp.fft(signal: n0.signal.clone()) { size: 1024 };
let n2 = dsp.window(signal: n0.signal) { type: "hann" };
let n3 = dsp.fft(signal: n2.windowed) { size: 1024 };