E1455, Refactoring the Chart helper

What it does: 
1) This helper/chart class provides the templates of data. It also has pie diagrams and charts for the data.
2) Also contains fixes to display bar, line and pie charts. 

Could you clarify on this? As per our understanding, these changes create a basic template with dummy values which then get replaced by the data variable being passed in the initialize call. 
I believe the original developers kept these values there to show future developers how the values should be for the chart to work. 
I was under the impression that yaml files are used for doing environment specific configuration things.