public Rect getContentRectMinusAxesMargins() {
        return contentRectMinusAxesMargins;
    }
Returns content rectangle with chart internal margins, for example for LineChart contentRectMinusAxesMargins is
bigger
than contentRectMinusAllMargins by point radius, thanks to that points are not cut on edges.

@see #setContentRect(int, int, int, int, int, int)
hellocharts-library/src/lecho/lib/hellocharts/computator/ChartComputator.java