Method initialize

resources/vega.min.js:14879–14896

(t, e, n, r, i)

        (this._defs = null));
    }
    initialize(t, e, n, r, i) {
      return (
        (this._defs = {}),
        this._clearDefs(),
        t &&
          ((this._svg = rv(t, 0, "svg", l_)),
          this._svg.setAttributeNS(u_, "xmlns", l_),
          this._svg.setAttributeNS(u_, "xmlns:xlink", uy["xmlns:xlink"]),
          this._svg.setAttribute("version", uy.version),
          this._svg.setAttribute("class", "marks"),
          iv(t, 1),
          (this._root = rv(this._svg, 0, "g", l_)),
          x_(this._root, s_),
          iv(this._svg, 1)),
        this.background(this._bgcolor),
        super.initialize(t, e, n, r, i)
      );
    }
    background(t) {
      return (
        arguments.length &&