JavaScript Dashed Spline Chart
Example showcasing use of DashedLine
style in a chart with two time series trends along the same Y axis.
This approach could be used in use cases with 1 "primary" trend, and 1 or more "supplementary" trends, which don't reflect the primary message of the data visualization but rather some "extra" information that may be useful along-side.
In this case, the dashed line style helps convey the message that this trend is not the main point to look at.