gestRootMagnitude(coef.a1, coef.a2);

        // Find n such that |r|^(2*n) <= eps.  That is, n = log(eps)/(2*log(r)).
        // Somewhat arbitrarily choose eps = 1e-20;
        let eps = 1e-20;
        let framesForTest =
            Math.floor(Math.log(eps) / (2 * Math.log(rootMagnitude)));

        // We're ready to create the graph for the test.  The offline context
        // has two channels: channel 0 is the expected (cascaded biquad) result
        // and channel 1 is the actual IIR filter result.
