public class Song
{
    /** Returns the song's artist */
    public String getArtist()
    { /* implementation not shown */ }

    /** Returns the length of the song in seconds */
    public int getSeconds()
    { /* implementation not shown */ }

    // There may be instance variables, constructors,
    // and methods that are not shown.
}

public class Playlist
{
    /** The songs in this playlist; guaranteed not null */
    private ArrayList<Song> songs;

    /** Removes every song by artist that is longer than
     *  maxSeconds, and returns the total number of seconds
     *  removed. Other songs keep their relative order.
     */
    public int trimArtist(String artist, int maxSeconds)
    { /* to be implemented */ }

    // There may be instance variables, constructors,
    // and methods that are not shown.
}