DialogBuilderFunc<T> typedef
DialogBuilderFunc<T> =
Widget Function(BuildContext, T)
To register a dialog you have to provide a builder function that
returns the content of the dialog that has this signatur.
The generic parameter T
defines the type of data that you want
to pass when the dialog should be displayed. It will be passed
to the builder function
Implementation
typedef DialogBuilderFunc<T> = Widget Function(BuildContext, T);