static parse(text) {
        text = text.replace(/\s/g, "");

        if (text.length < 4 || text.substr(0, 2) !== "{{" || text.substr(text.length - 2, 2) !== "}}") {
            throw new Error("Not surrounded by {{}}.");
        }

        // Some kind of recursive descent parser would be a better idea, but here we are.
        return Matrix.fromRows(text.
            substr(2, text.length - 4).
            split("},{").
            map(row => row.
                split(",").
                map(Complex.parse)));
    }
@param {!string} text
@returns {!Matrix}
@throws