class Protobuf::Field::BytesField

def encode(value)
  if value.is_a?(::Protobuf::Message)
    value = value.serialize_to_string
  else
    value = value.dup
    value.force_encoding(::Protobuf::Message::STRING_ENCODING) if value.respond_to?(:force_encoding)
  end
  string_size = VarintField.encode(value.size)
  string_size << value
end