This screenshot shows the Source pane in the Navigator. This image shows the files in an extension that extend Layouts defined in a dependency. The files extending the AccountContact Layout are highlighted in the image:

• data-description-x.js - This file extends the JavaScript functions that are used with the Layout's data source metadata.
• data-description-x.json - This file extends the JSON that describes the data source metadata for the Layout .
• layout-x.html - This file extends the HTML markup for the Layout's templates.
• layout-x.js - This file extends the JavaScript functions used in this Layout .
• layout-x.json - This file extends the JSON describing the Layout's metadata.