static from(v) {
        if (v instanceof Complex) {
            return v;
        }
        if (typeof v === "number") {
            return new Complex(v, 0);
        }
        throw new DetailedError("Unrecognized value type.", {v});
    }
Wraps the given number into a Complex value (unless it's already a Complex value).
@param {!number|!Complex} v
@returns {!Complex}