Toml.MetaTOML node metadata.
val id : t -> stringid m is a client defined identifier.
val tloc : t -> Serialkit_text.Tloc.ttloc m is the source location of the node it is attached to.
val v : ?init:t -> ?id:string -> ?tloc:Serialkit_text.Tloc.t -> unit -> tv ~init ?id ?tloc () has the values of ~init (defaults to none) overriden by specified arguments.