//lazy construction of instance
public static DatasourceHandler GetInstance()
{
if (_uniqueInstance == null)
{
_uniqueInstance = new DatasourceHandler();
}
return(_uniqueInstance);
}
public static DatasourceHandler GetInstance(Datasource datasource)
{
if (_uniqueInstance == null)
{
_uniqueInstance = new DatasourceHandler(datasource);
}
_datasource = datasource;
_datasource.LoadPeriods();
return(_uniqueInstance);
}