Implement Queue using two stack

package Queue;

import java.util.Stack;

public class QueueWithTwoStacks<T> {

Stack<T> s1 = new Stack<T>();
Stack<T> s2 = new Stack<T>();

public void enqueue(T data) {
s1.push(data);
}

public T dequeue() {
if (s2.empty()) {
while (!s1.isEmpty()) {
s2.push(s1.pop());
}

}
return s2.pop();
}

}