Stop reason for sampling completion.
Mirrors Python tinker.types.stop_reason.StopReason. Wire format: "length" | "stop"
"length"
"stop"
Parse wire format string to atom.
Convert atom to wire format string.
@type t() :: :length | :stop
@spec parse(String.t() | nil) :: t() | nil
@spec to_string(t()) :: String.t()