(merge_maybes (connection_string cfg1) (connection_string cfg2))
(merge_maybes (log_file cfg1) (log_file cfg2))
(merge_maybes (log_level cfg1) (log_level cfg2))
(merge_maybes (connection_string cfg1) (connection_string cfg2))
(merge_maybes (log_file cfg1) (log_file cfg2))
(merge_maybes (log_level cfg1) (log_level cfg2))