/// <summary>
 /// Create a new schedule entity with required attributes.
 /// </summary>
 /// <param name="name">Name of the new schedule</param>
 /// <param name="iterationLength">The duration an iteration will last in this schedule</param>
 /// <param name="iterationGap">The duration between iterations in this schedule.</param>
 /// <param name="attributes">Required attributes.</param>
 /// <returns>A newly minted Schedule that exists in the VersionOne system.</returns>
 public Schedule Schedule(string name, Duration iterationLength, Duration iterationGap,
     IDictionary<string, object> attributes) {
     var schedule = new Schedule(instance) {
         Name = name, 
         IterationLength = iterationLength, 
         IterationGap = iterationGap
     };
     AddAttributes(schedule, attributes);
     schedule.Save();
     return schedule;
 }