Building WPF Applications with Self-Tracking Entity Generator - Project Setup

using System;
using System.Collections.ObjectModel;
using System.ComponentModel;
using SchoolSample.EntityModel;

namespace SchoolSample.Common
{
    public interface ISchoolModel : INotifyPropertyChanged
    {
        // Data Retrieval:
        void GetStudentsAsync(string includeOption, string screenName);
        event EventHandler<ResultsArgs<Student>> GetStudentsCompleted;
        void GetStudentByIdAsync(int studentId);
        event EventHandler<ResultArgs<Student>> GetStudentByIdCompleted;

        void GetInstructorsAsync(string includeOption, string screenName);
        event EventHandler<ResultsArgs<Instructor>> GetInstructorsCompleted;
        void GetInstructorByIdAsync(int instructorId);
        event EventHandler<ResultArgs<Instructor>> GetInstructorByIdCompleted;

        void GetCoursesAsync(string screenName);
        event EventHandler<ResultsArgs<Course>> GetCoursesCompleted;
        void GetCourseByIdAsync(int courseId);
        event EventHandler<ResultArgs<Course>> GetCourseByIdCompleted;

        // Data Cache:
        ObservableCollection<Student> StudentsList { get; set; }
        Student CurrentStudent { get; set; }
        ObservableCollection<Instructor> InstructorsList { get; set; }
        Instructor CurrentInstructor { get; set; }
        ObservableCollection<Course> CoursesList { get; set; }
        Course CurrentCourse { get; set; }

        // Data Status:
        Boolean StudentsListHasChanges { get; }
        Boolean CurrentStudentHasChanges { get; }
        Boolean InstructorsListHasChanges { get; }
        Boolean CurrentInstructorHasChanges { get; }
        Boolean CoursesListHasChanges { get; }
        Boolean CurrentCourseHasChanges { get; }
        Boolean IsBusy { get; }

        // Update and Rollback of Entity List:
        void SaveStudentChangesAsync(bool allItems = true);
        event EventHandler<ResultArgs<string>> SaveStudentChangesCompleted;
        void RejectStudentChanges(bool allItems = true);

        void SaveInstructorChangesAsync(bool allItems = true);
        event EventHandler<ResultArgs<string>> SaveInstructorChangesCompleted;
        void RejectInstructorChanges(bool allItems = true);

        void SaveCourseChangesAsync(bool allItems = true);
        event EventHandler<ResultArgs<string>> SaveCourseChangesCompleted;
        void RejectCourseChanges(bool allItems = true);

        // Error Handling:
        Exception GetLastError();
        void ClearLastError();
        Boolean AllowMultipleErrors { get; set; }
    }
}