How to use the @nivo/line.LineDefaultProps.layers function in @nivo/line

defaultValue: defaults.areaBlendMode,
        controlType: 'blendMode',
        group: 'Style',
    },
    {
        key: 'layers',
        group: 'Customization',
        help: 'Defines the order of layers and add custom layers.',
        description: `
            You can also use this property to insert extra layers
            to the chart, this extra layer must be
            a function which will receive the chart
            computed data and must return a valid SVG element.
        `,
        required: false,
        defaultValue: defaults.layers,
    },
    {
        key: 'enablePoints',
        help: 'Enable/disable points.',
        type: 'boolean',
        required: false,
        defaultValue: defaults.enablePoints,
        controlType: 'switch',
        group: 'Points',
    },
    {
        key: 'pointSymbol',
        flavors: ['svg'],
        help:
            'Overrides default point circle. The function will receive `size`, `color`, `borderWidth` and `borderColor` props and must return a valid SVG element.',
        type: 'Function',