Removing short songs from a playlist

public class Song
{
    /** Returns the title of the song */
    public String getTitle()
    { /* implementation not shown */ }
 
    /** Returns the length of the song, in seconds (always greater than 0) */
    public int getSeconds()
    { /* implementation not shown */ }
 
    // There may be instance variables, constructors, and methods that are not shown.
}

public class Playlist
{
    /** The songs in the playlist, in play order; contains no null elements */
    private ArrayList<Song> songs;
 
    /**
     * Removes every song shorter than minSeconds from the playlist and
     * returns the total length, in seconds, of the songs removed.
     * The songs that are not removed stay in the same order.
     * Precondition: minSeconds > 0
     */
    public int removeShort(int minSeconds)
    { /* to be implemented */ }
 
    // There may be instance variables, constructors, and methods that are not shown.
}