asarkar

sealed abstract class BinaryTree
case class BinTreeLeaf(value: Int) extends BinaryTree
case class BinTreeNode(left: BinaryTree, right: BinaryTree) extends BinaryTree

def leafSum(tree: BinaryTree): Int = tree match {
 case node: BinTreeNode => leafSum(node.left) + leafSum(node.right)
 case leaf: BinTreeLeaf => leaf.value
}

"Method leafSum" should "traverse a binary tree in order" in {

asarkar

trait Logged { def log(msg: String) {} }

trait Chattery extends Logged { def chatter = log("I chatter. Do you mind?") }

trait ConsoleLogger extends Logged { override def log(msg: String) = println(msg) }

scala> val ch = new Chattery() with ConsoleLogger
ch: Chattery with ConsoleLogger = $anon$1@1ef7fe8e

scala> ch.chatter

asarkar

public class Employee {
  private Address addr;
  private int age;
  
  // Getters and setters
}

class Address {
  private String streetAddr1;
  private String streetAddr2;

asarkar

public class Fraction {
  private final int num;
  private final int denom;
  
  public Fraction(int num, int denom) {
    this.num = num;
    this.denom = denom;
  }
  
  public int getNum() {