public static void MergeCoverage(this StudyUnit curStudyUnit, StudyUnit newStudyUnit)
{
//Merge of the study range is different for each part
Coverage newCoverage = newStudyUnit.Coverage;
Coverage curCoverage = curStudyUnit.Coverage;
//1. Topical Coverage
CheckOption.Merge(newCoverage.Topics, curCoverage.Topics);
//2. Keyword
curCoverage.Keywords.AddRange(newCoverage.Keywords);
//3. Temporal Coverage
curCoverage.DateRange = newCoverage.DateRange;
//4. Geographic Levels Covered
CheckOption.Merge(newCoverage.Areas, curCoverage.Areas);
//5. Description
curCoverage.Memo = newCoverage.Memo;
}