// An unchecked exception class assumed by the textbook (and available 
// online as part of the JDSL library).

/** A BoundaryViolationException indicates that a Container's edges
 * were trespassed somehow: off the end, over the top, beyond the
 * bottom, etc.
 */

public class BoundaryViolationException extends RuntimeException {

  public BoundaryViolationException(String msg) {
    super(msg);
  }
}