In the following section of the Flutter style guide it suggests to put the widget's build method after all other methods, even the private ones that the build method uses. In theory it collides with a general rule of putting private class members after public class members. While developing real Flutter apps I've also noticed that if I want to fully understand a widget's private method, I usually need to start from going to a place where it's called.

What's a reason for putting build method after private methods that it uses?