Line Chart line width is unpredictable
The line chart's line width can be set by using the lineWidth property, however this property currently does not really reflect any sensible unit. In addition, the line width is dependent on the line chart's size and - even worse - on the amount of segments used for rendering the chart. This makes line width very unpredictable and behave in odd ways. Some way to handle it consistently should be found. Ideally, we would just specify line width in pixels.