can we animate SelectionShift when selecting a segment of pie chart?

[robertTyrell]

What did you do?

When selecting a section of a pie chart I would like the view to grow.

I have tried
` func chartValueSelected(_ chartView: ChartViewBase, entry: ChartDataEntry, highlight: Highlight) {
chartView.animate(xAxisDuration: 1)
// and also chartView.animate(yAxisDuration: 1)

}`

What did you expect to happen?

I was hoping when I selected a section of pie chart it would grow and shrink.

What happened instead?

The pie chart animation was redrawing itself around the centre of the chart.

Charts Environment

**Charts version/Branch/Commit Number:3.1.1
**Xcode version:9.3
**Swift version:4.1
Platform(s) running Charts:
**macOS version running Xcode:10.13.4

Demo Project

ℹ Please link to or upload a project we can download that reproduces the issue.

[liuxuan30]

#3290