Card constructor
Creates a Material Design card.
The elevation must be null or non-negative.
Implementation
const Card({
super.key,
this.color,
this.shadowColor,
this.surfaceTintColor,
this.elevation,
this.shape,
this.borderOnForeground = true,
this.margin,
this.clipBehavior,
this.child,
this.semanticContainer = true,
}) : assert(elevation == null || elevation >= 0.0),
_variant = _CardVariant.elevated;