at method
Returns the value associated with key at the column index.
final lookup = WebSocketManagerLookup();
final key = MultiKey(['a', 'b', 'c']);
lookup[key] = 1000;
print(lookup['a']); // 1000
print(lookup['b']); // 1000
print(lookup['e']); // null
Implementation
V? at(final dynamic key, { required final int index }) {
predicate(final K multiKey) => multiKey.containsAt(key, index: index);
return _find(predicate)?.value;
}