### Question:
MerkleTree { public List<Node> getNodes() { return nodes; } MerkleTree(MessageDigest digest);  MerkleTree(MessageDigest digest, List<byte[]> dataList); List<Node> getNodes(); List<Node> getLeaves(); Node getRoot(); void appendLeaf(Node node); void appendLeaves(Node[] nodes); void appendLeaf(byte[] value); void appendLeaves(byte[][] values); void appendHashedLeaves(byte[][] hashes); @Override boolean equals(Object o);  }### Answer:
@Test public void testCreateEmptyTree() { MerkleTree tree = new MerkleTree(sha256()); List<Node> nodes = tree.getNodes(); Assertions.assertEquals(0, nodes.size()); }