Could we test it against the props['nticks'] that you define in this function? 

```
fig = plt.figure()
ax = plt.axes(xticks=[])
nticks = len(ax.xaxis.get_major_locator()())
sizes = [tick.get_fontsize() for tick in ax.xaxis.get_ticklabels()]
if nticks > 0 and sizes[1:] == sizes[:-1]:
    print sizes[0]
```