A place of a Petri net.
id is the place's identifier (an atom or a string) and name an optional human-readable label, carried through PNML as the <name> element.
id
name
<name>
Opaque interchange elements kept for round-tripping; see Petrex.PNML.
Petrex.PNML
@type extra() :: [term()]
@type id() :: atom() | String.t()
@type t() :: %Petrex.Place{extra: extra(), id: id(), name: String.t() | nil}