@staticmethod<EOL><INDENT>def prefetch_courses(persistent_course_grades):<DEDENT>
return CourseOverview.get_from_ids_if_exists(<EOL>[grade.course_id for grade in persistent_course_grades]<EOL>)<EOL>
Prefetch courses from the list of course_ids present in the persistent_course_grades.

Arguments:
    persistent_course_grades (list): A list of PersistentCourseGrade.

Returns:
    (dict): A dictionary containing course_id to course_overview mapping.