@Test(expected = IllegalArgumentException.class) public void shouldNotAcceptNullBinaryNodes() { binaryTreeDepth.get(null); }
public int get(BinaryNode root) { if (root == null) { throw new IllegalArgumentException("You can't pass a null BinaryNode as parameter"); } return getInner(root); }
BinaryTreeDepth { public int get(BinaryNode root) { if (root == null) { throw new IllegalArgumentException("You can't pass a null BinaryNode as parameter"); } return getInner(root); } }
BinaryTreeDepth { public int get(BinaryNode root) { if (root == null) { throw new IllegalArgumentException("You can't pass a null BinaryNode as parameter"); } return getInner(root); }  }
BinaryTreeDepth { public int get(BinaryNode root) { if (root == null) { throw new IllegalArgumentException("You can't pass a null BinaryNode as parameter"); } return getInner(root); }  int get(BinaryNode root); }
BinaryTreeDepth { public int get(BinaryNode root) { if (root == null) { throw new IllegalArgumentException("You can't pass a null BinaryNode as parameter"); } return getInner(root); }  int get(BinaryNode root);  }