public BTNode getHead() {
BTNode node1 = new BTNode(1);
BTNode node2 = new BTNode(2);
BTNode node3 = new BTNode(3);
BTNode node4 = new BTNode(4);
BTNode node5 = new BTNode(5);
BTNode node6 = new BTNode(6);
BTNode node7 = new BTNode(7);
node1.leftNode = node2;
node1.rightNode = node3;
node2.leftNode = node4;
node2.rightNode = node5;
node3.leftNode = node6;
node3.rightNode = node7;
return node1;
}
