Logs_fmtval reporter :
?pp_header:(Logs.level * string option) Fmt.t ->
?app:Format.formatter ->
?dst:Format.formatter ->
unit ->
Logs.reporterval app_style : Fmt.styleval err_style : Fmt.styleval warn_style : Fmt.styleval info_style : Fmt.styleval debug_style : Fmt.styleval pp_header : (Logs.level * string option) Fmt.t