t() :: %Protobuf.MessageProps{
  embedded_fields: [atom()],
  enum?: boolean(),
  extendable?: boolean(),
  field_props: %{required(integer()) => Protobuf.FieldProps.T},
  field_tags: %{required(atom()) => integer()},
  map?: boolean(),
  oneof: [{atom(), non_neg_integer()}],
  ordered_tags: [integer()],
  repeated_fields: [atom()],
  syntax: atom(),
  tags_map: %{required(integer()) => integer()}
}