How to use the @nivo/sunburst.SunburstDefaultProps.identity function in @nivo/sunburst

},
    {
        key: 'identity',
        group: 'Base',
        help: 'Id accessor.',
        description: `
            define identity accessor, if string given,
            will use \`node[value]\`,
            if function given, it will be invoked
            for each node and will receive the node as
            first argument, it must return the node
            identity (string).
        `,
        type: 'string | Function',
        required: false,
        defaultValue: defaults.identity,
    },
    {
        key: 'value',
        group: 'Base',
        help: 'Value accessor',
        description: `
            define value accessor, if string given,
            will use \`node[value]\`,
            if function given, it will be invoked
            for each node and will receive the node as
            first argument, it must return the node
            value (number).
        `,
        type: 'string | Function',
        required: false,
        defaultValue: defaults.value,