function testMapPropertyToField()
 {
     $course = new CourseForTest();
     $this->assertEqual('lectures', $course->mapFieldToProperty('course_id'));
     $this->assertNull($course->mapFieldToProperty('blah'));
     $lecture = new LectureForTest();
     $this->assertEqual('course', $lecture->mapFieldToProperty('course_id'));
     $this->assertNull($lecture->mapFieldToProperty('blah'));
 }