In Power Query Editor, you have a Customers table with an Email column containing values like "jsmith@contoso.com" and "mlee@fabrikam.net". You need to create a new column that contains only the domain portion (e.g., "contoso.com") for grouping customers by company. You are not confident writing the extraction expression manually. Which Power Query feature lets you build this transform by typing sample output values so the engine infers the M code?