addContainer method
Adds a container with nested content.
Containers provide visual grouping with optional color theming and
spoiler protection. The nested builder must not contain components that
are top-level-only like AttachedFile or Section.
Example:
final nested = MessageBuilder()
..addText('This content is in a container')
..addText('With a blue background');
builder.addContainer(
builder: nested,
color: Color.blue,
spoiler: false,
);
Implementation
void addContainer({
required MessageBuilder builder,
Color? color,
bool? spoiler,
}) {
_components.add(Container(color, spoiler, builder));
}