bool DataStorePrivate::GetPositionInStorageForIndex(const BaseType& dataStorage, uint& lineNumber, uint& indexInLine, uint index)
{
    indexInLine = index;
    lineNumber = 0;

    uint dataStorageSize = dataStorage.size();
    uint lineSize = 0;
    while (lineNumber < dataStorageSize &&
            indexInLine >= (lineSize = dataStorage[lineNumber]->size()))
    {
        indexInLine -= lineSize;
        lineNumber++;
    }
    return lineNumber < dataStorageSize;
}
    /// Returns the number of elements in the map.
    virtual size_type size() const
	{return _base.size();}