question: @ SuppressWarnings ( "unchecked" ) public List < Boundary > populateArea ( final Long wardId ) { HierarchyType hType = heirarchyTypeService . getHierarchyTypeByName ( hierarchyTypeName ) ; ; List < Boundary > areaList = new LinkedList < Boundary > ( ) ; final BoundaryType childBoundaryType = boundaryTypeService . getBoundaryTypeByNameAndHierarchyType ( "Area" , hType ) ; final Boundary parentBoundary = boundaryService . getBoundaryById ( wardId ) ; areaList = new LinkedList ( crossHeirarchyService . getCrossHierarchyChildrens ( parentBoundary , childBoundaryType ) ) ; LOGGER . info ( "***********Ajax AreaList: " + areaList . toString ( ) ) ; return areaList ; }
target:  Populate the Area list by ward