IZdcGeometryDB Node1 IZdcGeometryDB # m_geoLoaded # m_mainJson + IZdcGeometryDB() + getDB() Node2 ZdcFileGeometryDB - m_fileStr + ZdcFileGeometryDB() + loadJSONFile() + getInstance() Node1->Node2 Node3 ZdcGeoDBGeometryDB   + ZdcGeoDBGeometryDB() + loadGeoDB() + getInstance() Node1->Node3