Sandwich blt = new Sandwich("BLT", Bread.WHEAT, 3);
blt.addCondiment(Condiment.MAYO);
blt.addMeat(Meat.BACON);
blt.addVegetable(Vegetable.Lettuce);
blt.addVegetable(Vegetable.Tomato);

. . .

public class Sandwich {

    // private instance variables

    public Sandwich() { }

    public Sandwich(String name) {
        this();
        this.name = name;
    }
    
    // telescoping constructors
    public Sandwich(String name, Bread bread) {
        this(name, bread, bread.minNumSlices);
    }
    
    public Sandwich(String name, Bread bread, int numSlices) {
        this(name);
        this.bread = bread;
        this.numBreadSlices = numSlices;
    }

    public void addCondiment(Condiment meat) { ... }
    public void addMeat(Meat meat) { ... }
    public void addVegetable(Vegetable veggie) { ... }
}

Sandwich blt = new Sandwich.Builder()
.name("BLT")
.bread(Bread.WHEAT)
.numBreadSlices(3)
.withCondiment(Condiment.MAYO)
.withMeat(Meat.BACON)
.withVegetable(Vegetable.Lettuce)
.withVegetable(Vegetable.Tomato)
.build();

. . .

public class Sandwich {

    // private instance variables

    public Sandwich() { }

    public void addCondiment(Condiment meat) { ... }
    public void addMeat(Meat meat) { ... }
    public void addVegetable(Vegetable veggie) { ... }

    public class Builder {

        public Sandwich build() {
            Sandwich s = new Sandwich();
            s.setName(this.name);
            ...
            return s;
        }

        public SandwichBuilder withBread();

    }

}

// Quartz scheduler Trigger builder
public T build() {
    if(scheduleBuilder == null)
        scheduleBuilder = SimpleScheduleBuilder.simpleSchedule();
    MutableTrigger trig = scheduleBuilder.build();
  
    trig.setCalendarName(calendarName);
    trig.setDescription(description);
    trig.setEndTime(endTime);
    if(key == null)
        key = new TriggerKey(Key.createUniqueName(null), null);
    trig.setKey(key); 
    if(jobKey != null)
        trig.setJobKey(jobKey);
    trig.setPriority(priority);
    trig.setStartTime(startTime);

    if(!jobDataMap.isEmpty())
        trig.setJobDataMap(jobDataMap);
   
    return (T) trig;
}
    

// Build then schedule a Job and a Trigger
JobDetail job = newJob(MyJob.class)
    .withIdentity("myJob")
    .build();
         
Trigger trigger = newTrigger() 
    .withIdentity(triggerKey("myTrigger", "myTriggerGroup"))
    .withSchedule(simpleSchedule()
        .withIntervalInHours(1)
        .repeatForever())
    .startAt(futureDate(10, MINUTES))
    .build();
 
scheduler.scheduleJob(job, trigger);

public double calculate(Operator op, double firstOperand, double secondOperand) {
    switch (op) {
        case ADD:
            return firstOperand + secondOperand;
        case SUBTRACT:
            return firstOperand - secondOperand;
        case MULTIPLY:
            return firstOperand * secondOperand;
        case DIVIDE:
            return firstOperand / secondOperand;
    }
}

public class AdditionStrategy implements CalculationStrategy {

    @Override
    public double calculate(double firstOperand, double secondOperand) {
        return firstOperand + secondOperand;
    }
}

. . .

public double calculate(CalculationStrategy strat, double firstOperand, double secondOperand) {
    return strat.calculate(firstOperand, secondOperand);
}