merge method

other applied after this one: its entries and curves win, the longer duration is kept.

Implementation

MarkerTransition merge(MarkerTransition other) => MarkerTransition(
  duration: other.duration > duration ? other.duration : duration,
  appearFrom: {...appearFrom, ...other.appearFrom},
  disappearTo: {...disappearTo, ...other.disappearTo},
  moveCurve: other.moveCurve,
  fadeInCurve: other.fadeInCurve,
  fadeOutCurve: other.fadeOutCurve,
);