public class Video { private String title; private int length; public Video(String title, int length) { setTitle(title); setLength(length); } public void setTitle(String title) { if (title == null) throw new IllegalArgumentException("null title"); this.title = title; } public String getTitle() { return title; } public void setLength(int length) { if (length < 0) throw new IllegalArgumentException("negative length"); this.length = length; } public int getLength() { return length; } public String toString() { return "Video: title: " + title + " length: " + length; } public boolean equals(Object rhs) { if (rhs instanceof Video) { Video v = (Video) rhs; return title.equals(v.title) && length == v.length; } return false; } }