uncheck method
取消选中
Implementation
void uncheck({int? position, E? checkItem}) {
assert(null != position || null != checkItem);
if (null != position) {
assert(position < size);
checkItem = item(position);
} else {
position = indexOfItem(checkItem!);
}
if (null != checkItem && _checks.contains(checkItem)) {
_checks.remove(checkItem);
notifyItemChanged(position);
}
}