getConstraints function Null safety
Implementation
Map<String, dynamic> getConstraints(String key, Map<String, dynamic> v, value) {
v.addAll({
key: BoxConstraints(
maxHeight: value['maxH'] ?? double.infinity,
maxWidth: value['maxW'] ?? double.infinity,
minHeight: value['minH'] ?? 0,
minWidth: value['minW'] ?? 0),
});
return v;
}