Keeping a to-do list in priority order

public class Task
{
    /** Returns the name of the task */
    public String getName()
    { /* implementation not shown */ }
 
    /** Returns the priority of the task, an integer from 0 to 10 */
    public int getPriority()
    { /* implementation not shown */ }
 
    // There may be instance variables, constructors, and methods that are not shown.
}

public class TaskList
{
    /**
     * The tasks, sorted from highest to lowest priority; tasks with
     * equal priority are in the order they were added.
     * Contains no null elements; may be empty.
     */
    private ArrayList<Task> tasks;
 
    /**
     * Inserts t into tasks so that tasks stays sorted as described.
     * t goes after every task that has the same priority as t.
     * Precondition: t is not null.
     */
    public void addTask(Task t)
    { /* to be implemented */ }
 
    // There may be instance variables, constructors, and methods that are not shown.
}