How to use the @nivo/pie.PieDefaultProps.cornerRadius function in @nivo/pie

defaultValue: defaults.padAngle,
        controlType: 'range',
        group: 'Base',
        controlOptions: {
            unit: '°',
            min: 0,
            max: 45,
            step: 1,
        },
    },
    {
        key: 'cornerRadius',
        help: 'Rounded slices.',
        type: 'number',
        required: false,
        defaultValue: defaults.cornerRadius,
        controlType: 'range',
        group: 'Base',
        controlOptions: {
            unit: 'px',
            min: 0,
            max: 45,
            step: 1,
        },
    },
    {
        key: 'sortByValue',
        help: `If 'true', arcs will be ordered according to their associated value.`,
        type: 'boolean',
        required: false,
        defaultValue: defaults.sortByValue,
        controlType: 'switch',