Is it possible to apply a custom label for each data series in billboard.js? As opposed to using the value, id, or index of the data point in the series?

I've been using the following billboard.js documentation for reference: https://naver.github.io/billboard.js/release/latest/doc/Options.html#.data%25E2%2580%25A4labels

https://naver.github.io/billboard.js/demo/#Data.DataLabelFormat

data: {
  labels: true,

  // or set specific options
  labels: {
   format: function(v, id, i, j) {
    ...
    // to multiline, return with '\n' character
    return "Line1\nLine2";
   },

   // it's possible to set for each data
   format: {
    data1: function(v, id, i, texts) { ... },
    ...
    },
  }
}

In the above snippet, texts is described as "the array of whole corresponding data series' text labels". But the parameter seems empty and I'm not sure how to pass in an array of text labels. For example, I'm working with data that includes a city, Country. Would it be possible to have the legend/tile = city and the label = country.