/// <summary>
        /// Checks if student completes a certain course taken requirement. The requirement is completed if the HistoricalCodeId of the required course is the same as
        /// a the HistoricalCodeId of an element from the studentCourses taken list. Or if current course registration period is preregistation and the HistoricalCodeId of the
        /// required coruse is the same as the HistoricalCodeId of an element from coursesInProgress list.
        /// </summary>
        /// <param name="requirement">The requirement entity.</param>
        /// <param name="studentCoursesTaken">All student taken courses.</param>
        /// <param name="currentRegPeriod">Current registration period.</param>
        /// <param name="coursesInProgress">All student courses INPROGRESS.</param>
        /// <returns> TRUE if the requirement is completed and FALSE if the requirement is not completed.</returns>
        private bool CheckIfCourseTakenRequirementIsCompleted(view_courseTakenRegReqs requirement, List<view_studentCoursesTaken> studentCoursesTaken, CourseRegPeriods currentRegPeriod, IEnumerable<view_studentCoursesTaken> coursesInProgress)
        {
            //1. Get the required course, the required grade and the required course code.
            var requiredCourseId = requirement.RequiredCourseId;
            var requiredGrade = requirement.MinimalGrade;
            var requiredHistoricalCodeId = requirement.RequiredHistoricalCodeId;

            //2. All possible at AUBG
            var possibleGrades = new List<string>
            {
                "F", "D", "D+", "C-", "C", "C+", "B-", "B", "B+", "A-", "A"
            };

            //3. Check if student has taken the course
            foreach (var studentCourseTaken in studentCoursesTaken)
            {
                //3.1. Does the requirement include a grade.
                bool checkForGrade = (requiredGrade != String.Empty) ? true : false;

                //TODO: Ask registrars about the different bases and grade requirement
                if (!checkForGrade)
                {
                    //TODO-Lazov - what about pass-fail
                    if ((requiredHistoricalCodeId == studentCourseTaken.HistoricalCodeId) && ((CourseBases)studentCourseTaken.BasisId == CourseBases.Credit))
                    {
                        return true;
                    }
                }
                else
                {
                    var requiredGradePosition = possibleGrades.IndexOf(requiredGrade);
                    var achievedGradePosition = possibleGrades.IndexOf(studentCourseTaken.Grade);

                    if ((requiredHistoricalCodeId == studentCourseTaken.HistoricalCodeId) && (requiredGradePosition <= achievedGradePosition) && ((CourseBases)studentCourseTaken.BasisId == CourseBases.Credit))
                    {
                        return true;
                    }
                }
            }

            //TODO-Lazov There was another requirement about course allowing to be counted as taken if it's been currently been taken
            // If during pre-registration, then check if the student is not taking the course now
            if ((currentRegPeriod == CourseRegPeriods.PreRegistration) && (requirement.CountCoursesInProgress == true))
            {
                foreach (var course in coursesInProgress)
                {
                    if ((requiredHistoricalCodeId == course.HistoricalCodeId))
                    {
                        return true;
                    }
                }
            }

            return false;
        }