private void swap(Node node1,Node node2){
        int weight = node1.weight;
        T data = node1.key;
        
        node1.key = node2.key;
        node1.weight = node2.weight;
        
        node2.key = data;
        node2.weight = weight;
    }
Extract min value key from the heap
src/com/interview/graph/BinaryMinHeap.java