Section constructor

Section({
  1. required MessageBuilder builder,
  2. Button? button,
  3. Thumbnail? thumbnail,
})

Implementation

Section({required this.builder, Button? button, Thumbnail? thumbnail})
  : assert(
      button == null || thumbnail == null,
      'Accessory must be either a button or a thumbnail, not both.',
    ),
    _button = button,
    _thumbnail = thumbnail;