CompoundAnimation<T> constructor

CompoundAnimation<T>({@required Animation<T> first, @required Animation<T> next })

Creates a CompoundAnimation. Both arguments must be non-null. Either can be a CompoundAnimation itself to combine multiple animations.

Implementation 

CompoundAnimation({
  @required this.first,
  @required this.next,
}) : assert(first != null),
     assert(next != null);