fade method
Adds a FadeEffect that animates the opacity of the target between the
specified begin
and end
values (via FadeTransition).
Implementation
T fade({
Duration? delay,
Duration? duration,
Curve? curve,
double? begin,
double? end,
}) =>
addEffect(FadeEffect(
delay: delay,
duration: duration,
curve: curve,
begin: begin,
end: end,
));