constructor (parent, chartGroup) {
        super();

        this._section = null;
        this._size = 999; // shouldn't be needed, but you might
        this._html = function (d) {
            return `you need to provide an html() handling param:  ${JSON.stringify(d)}`;
        };
        this._sortBy = function (d) {
            return d;
        };
        this._order = ascending;
        this._beginSlice = 0;
        this._endSlice = undefined;

        this._htmlSection = d => `<div class='${SECTION_CSS_CLASS}'><h1 class='${LABEL_CSS_CLASS}'>${ 
            this.keyAccessor()(d)}</h1></div>`;

        this._mandatoryAttributes(['dimension', 'section']);

        this.anchor(parent, chartGroup);
    }
Create a Data Grid.
@param {String|node|d3.selection} parent - Any valid
{@link https://github.com/d3/d3-selection/blob/master/README.md#select d3 single selector} specifying
a dom block element such as a div; or a dom element or d3 selection.
@param {String} [chartGroup] - The name of the chart group this chart instance should be placed in.
Interaction with a chart will only trigger events and redraws within the chart's group.