How to use the @nivo/bump.AreaBumpDefaultProps.borderColor function in @nivo/bump

controlType: 'lineWidth',
    },
    {
        key: 'inactiveBorderWidth',
        group: 'Style',
        type: 'number | (serie: Serie) => number',
        help: 'Area border width for inactive series.',
        defaultValue: defaults.inactiveBorderWidth,
        controlType: 'lineWidth',
    },
    {
        key: 'borderColor',
        help: 'Method to compute area border color.',
        type: 'string | object | Function',
        required: false,
        defaultValue: defaults.borderColor,
        controlType: 'inheritedColor',
        group: 'Style',
    },
    {
        key: 'borderOpacity',
        group: 'Style',
        type: 'number | (serie: Serie) => number',
        help: 'Area border opacity.',
        defaultValue: defaults.borderOpacity,
        controlType: 'opacity',
    },
    {
        key: 'activeBorderOpacity',
        group: 'Style',
        type: 'number | (serie: Serie) => number',
        help: 'Area border opacity for active series.',

},

    align: AreaBumpDefaultProps.align,
    interpolation: AreaBumpDefaultProps.interpolation,
    spacing: 8,
    xPadding: AreaBumpDefaultProps.xPadding,

    colors: { scheme: 'nivo' },
    blendMode: 'multiply',
    fillOpacity: AreaBumpDefaultProps.fillOpacity,
    activeFillOpacity: AreaBumpDefaultProps.activeFillOpacity,
    inactiveFillOpacity: AreaBumpDefaultProps.inactiveFillOpacity,
    borderWidth: AreaBumpDefaultProps.borderWidth,
    activeBorderWidth: AreaBumpDefaultProps.activeBorderWidth,
    inactiveBorderWidth: AreaBumpDefaultProps.inactiveBorderWidth,
    borderColor: AreaBumpDefaultProps.borderColor,
    borderOpacity: AreaBumpDefaultProps.borderOpacity,
    activeBorderOpacity: AreaBumpDefaultProps.activeBorderOpacity,
    inactiveBorderOpacity: AreaBumpDefaultProps.inactiveBorderOpacity,

    startLabel: 'id',
    startLabelPadding: AreaBumpDefaultProps.startLabelPadding,
    startLabelTextColor: AreaBumpDefaultProps.startLabelTextColor,
    endLabel: 'id',
    endLabelPadding: AreaBumpDefaultProps.endLabelPadding,
    endLabelTextColor: AreaBumpDefaultProps.endLabelTextColor,

    enableGridX: AreaBumpDefaultProps.enableGridX,
    axisTop: {
        enable: true,
        tickSize: 5,
        tickPadding: 5,