price_tab.dart

Widget _buildPlane() {
  return AnimatedBuilder(
    animation: _planeTravelAnimation,
    child: Column(
      children: <Widget>[
        AnimatedPlaneIcon(animation: _planeSizeAnimation),
        Container(
          width: 2.0,
          height: 240.0,
          color: Color.fromARGB(255, 200, 200, 200),
        ),
      ],
    ),
    [...]
  );
}