titlePadding property
Padding around the title.
If there is no title, no padding will be provided. Otherwise, this padding is used.
This property defaults to providing 24 pixels on the top, left, and right of the title. If the content is not null, then no bottom padding is provided (but see contentPadding). If it is null, then an extra 20 pixels of bottom padding is added to separate the title from the actions.
Implementation
final EdgeInsetsGeometry? titlePadding;