none method
Returns true if there is no entries in the map that match the given predicate.
predicate must not be null.
Implementation
bool none(bool Function(K key, V value) predicate) {
if (isEmpty) {
return true;
}
for (final MapEntry<K, V> entry in entries) {
if (predicate(entry.key, entry.value)) {
return false;
}
}
return true;
}