This multi-part tutorial covers the creation of a new data source extension for Power Query. The tutorial is meant to be done sequentially � each lesson builds on the connector created in previous lessons, incrementally adding new capabilities to your connector.

In this lesson, you will:

• Enforce a table schema using M Types
• Set types for nested records and lists
• Refactor code for reuse and unit testing

Please follow the tutorial at Microsoft Docs for Power Query here.