/**
 * A class to implement a combination lock with 26 dial positions
 * and a three-letter combination
 * 
 * @author your name
 */
public class CombinationLock
{
   // instance variable declarations go here
 
  /**
   * Creates a lock with a given combination consisting of three upper-case characters.
   * @param first the first letter of the combination
   * @param second the second letter of the combination
   * @param third the third letter of the combination
   */
   public CombinationLock(String first, String second, String third)
   {
      // TO DO: write method body
   }

  /**
   * Set the dial to a position
   * @param aPosition a String consisting of a single uppercase letter (A..Z)
   */
   public void setPosition(String aPosition)
   {
      // TO DO: write method body
   }

  /**
   * Try opening the lock
   */
   public void tryToOpen()
   {
      // TO DO: write method body
   }

  /**
   * Check whether the lock is open
   * @return true or false indicating whether the lock is open
   */
   public boolean isOpen()
   {
      // TO DO: write method body
   }

  /**
   * Close the lock and print a message indicating that the lock is now closed
   */
   public void lock()
   {
      // TO DO: write method body
   }
}