R Highcharter如何为多个y轴定制工具提示？

library(highcharter)

# 创建一个Highchart对象
chart <- highchart() %>%
  # 添加y轴
  hc_yAxis_multiples(
    list(title = list(text = "Y轴1")),
    list(title = list(text = "Y轴2"))
  ) %>%
  # 添加数据系列
  hc_add_series(
    type = "line",
    data = c(1, 2, 3, 4, 5),
    yAxis = 0,
    name = "数据系列1"
  ) %>%
  hc_add_series(
    type = "line",
    data = c(6, 7, 8, 9, 10),
    yAxis = 1,
    name = "数据系列2"
  ) %>%
  # 定制工具提示
  hc_tooltip(
    shared = TRUE,
    useHTML = TRUE,
    headerFormat = "<b>{point.key}</b><br>",
    pointFormat = "<span style='color:{series.color}'>{series.name}: </span>{point.y}<br>"
  )

# 输出图表
chart