Function encode_copy_csv_cells_opts 

pub fn encode_copy_csv_cells_opts(
    cells: &[Option<String>],
    delimiter: char,
    quote: char,
    escape: char,
    force_quote: Option<&[bool]>,
    null_str: &str,
) -> String

v7.39 (round 247) — the full CSV cell encoder: escape is the character that precedes a quote (or itself) inside a quoted cell (PG’s default is the quote itself — doubling), and force_quote marks per-column forced quoting (NULLs stay bare, as PG’s FORCE_QUOTE does).