t() :: %Pbuf.Protoc.Field{
  decode_fun: String.t(),
  default: String.t(),
  encode_fun: String.t(),
  hidden: boolean(),
  json?: term(),
  name: String.t(),
  oneof_index: nil | non_neg_integer(),
  post_decode: :none | :map | :repack | :oneof1 | :oneof2,
  prefix: binary(),
  tag: pos_integer(),
  typespec: String.t()
}