Showing an empty axis group in box plots

plotly.js
1

Hello,

I’m trying to show an empty axis group in a box plot (indicating “data unavailable”). Here’s my attempt - there should be a tick mark for “day 1” with no box above it:

var trace1 = {
  y: [
    null,
    0.2, 0.7, 0.9, 0.1, 0.5, 0.3],
  x: [
    'day 1',
    'day 2', 'day 2', 'day 2', 'day 2', 'day 2', 'day 2'],
  name: 'kale',
  type: 'box',
  boxpoints: 'all'
};

var data = [trace1];

var layout = {
  boxmode: 'group'
};

Plotly.newPlot('myDiv', data, layout);

https://jsfiddle.net/c51h4w7g/

Plotly doesn’t show “day 1” at all. I also unsuccessful tried supplying layout.xaxis.tickvals/ticktext.

Is this possible?

Thank you.