折线图和柱状图的tickCount显示不准确

使用分组柱状图或者对比折线图都有这个问题
tickCount值比较小时是对应的，但是当接近横坐标最大数量时就会出现数量和tickCount值不一样的问题。这是bug还是为了合理显示这么处理的？

Start by reproducing the reported behavior with a grouped bar chart and a comparison line chart, especially when tickCount approaches the number of x-axis categories. Inspect the axis tick-count handling and compare the rendered tick total with the requested value; done requires either correcting the discrepancy or documenting the intended behavior with a reproducible test.

Written by the indexing model from the issue text.