我正在制作一个图表来显示某公司的收入，我想显示今年的预测，但要使用borderDash段选项。我该怎么做呢？我试过了，但我不知道该怎么做。

const lineCanvas = document.getElementById("lineCanvas");

const prediction = (ctx, value) => ctx.dataIndex = 4 ? value : undefined;

const lineChart = new Chart(lineCanvas, {
type: "line",
data: {
    labels: ["2019", "2020", "2021", "2022"],
    datasets: [{
        label: "Revenues",
        data: [2195, 2225, 2166, 2250],
        backgroundColor: "orange",
        borderColor: "orange",
        segment: {
            borderDash: ctx => prediction(ctx, [6, 6])
        }
    }]
},
options: {
    scales: {
        y: {
            ticks: {
                font: {
                    size: 18
                },
                stepSize: 10
            },
            title: {
                display: true,
                text: "Total",
                font: {
                    size: 14
                }
            },

        },
        x: {
            ticks: {
                font: {
                    size: 18
                }
            },
            title: {
                display: true,
                text: "Year",
                font: {
                    size: 14
                }
            }
        }
    },
    plugins: {
        title: {
            display: true,
            text: "Company's Revenues",
            font: {
                size: 22
            },
            padding: 0
        },
        subtitle: {
            display: true,
            text: "(in millions of €)",
            font: {
                size: 18
            },
            padding: 0
        }
    }
}
});

以下是预期结果：Image of the expected result
我希望有人能帮我。提前感谢。