As discussed with @kitaisreal 
{
    comment = comment_;
}
void StorageInMemoryMetadata::setColumns(ColumnsDescription columns_)
{
    if (columns_.getAllPhysical().empty())
        throw Exception("Empty list of columns passed", ErrorCodes::EMPTY_LIST_OF_COLUMNS_PASSED);
    columns = std::move(columns_);
}
void StorageInMemoryMetadata::setSecondaryIndices(IndicesDescription secondary_indices_)