How can I get the data?

Hello, guys. Help me, please. I have this default code in file visual.ts:

module powerbi.extensibility.visual {

    export class Visual implements IVisual {
        private target: HTMLElement;
        private updateCount: number;

        constructor(options: VisualConstructorOptions) {
            console.log('Visual constructor', options);
            this.target = options.element;
            this.updateCount = 0;
        }

        public update(options: VisualUpdateOptions) {
            console.log('Visual update', options);
            this.target.innerHTML = `<p>Update count: <em>${(this.updateCount++)}</em></p><br>`;
        }
    }
}

And this default code in file capabilities.json:

{
    "dataRoles": [
        {
            "displayName": "Category Data",
            "name": "category",
            "kind": "Grouping"
        },
        {
            "displayName": "Measure Data",
            "name": "measure",
            "kind": "Measure"
        }
    ],
    "dataViewMappings": [
        {
            "categorical": {
                "categories": {
                    "for": {
                        "in": "category"
                    },
                    "dataReductionAlgorithm": {
                        "top": {}
                    }
                },
                "values": {
                    "select": [
                        {
                            "bind": {
                                "to": "measure"
                            }
                        }
                    ]
                }
            }
        }
    ]
}

What I have to do to get any data in visualization? I need just get the data.