# LinkedQueue<E> constructor

LinkedQueue<E>([

1. E? defaultValue

])

Creates an empty LinkedQueue.

A queue implementation using a linked list structure, mimicking Java's LinkedList as Queue.

This implementation provides efficient queue operations with constant-time insertion and removal at both ends. It uses a doubly-linked list internally for optimal performance.

## Key Features:

- Constant-time operations: O(1) for offer, poll, peek
- Memory efficient: Only allocates nodes as needed
- Unbounded: Can grow to any size (limited by available memory)
- FIFO ordering: First element added is first to be removed

## Usage Examples:

    final queue = LinkedQueue<String>();

    // Add elements to the queue
    queue.offer('first');
    queue.offer('second');
    queue.offer('third');

    // Process elements in FIFO order
    while (!queue.isEmpty) {
      print(queue.poll()); // first, second, third
    }

    // Peek without removing
    queue.offer('peek-me');
    print(queue.peek()); // 'peek-me'
    print(queue.size()); // 1

## Implementation

    LinkedQueue([E? defaultValue]) : _defaultValue = defaultValue;