| When serializing bytes from a `MessageLite`, one can use `toByteString` to get a |
| `ByteString`, effectively an immutable wrapper over a `byte[]`. This ByteString |
| can be passed around and deserialized into a message using |
| [`MyMessage.Builder.mergeFrom(ByteString)`][merge]. |
| |
| [`ByteString#toStringUtf8`] copies UTF-8 encoded byte data living inside the |
| `ByteString` to a `java.lang.String`, replacing any |
| [invalid UTF-8 byte sequences][invalid-utf8-byte-sequences] with � (the Unicode |
| replacement character). |
| |
| In this circumstance, a protocol message is being serialized to a `ByteString`, |
| then immediately turned into a Java `String` using the `toStringUtf8` method. |
| However, serialized protocol buffers are arbitrary binary data and not |
| UTF-8-encoded data. Thus, the resulting `String` may not match the actual |
| serialized bytes from the protocol message. |
| |
| Instead of holding the serialized protocol message in a Java `String`, carry |
| around the actual bytes in a `ByteString`, `byte[]`, or some other equivalent |
| container for arbitrary binary data. |
| |
| [merge]: https://developers.google.com/protocol-buffers/docs/reference/java/com/google/protobuf/Message.Builder#mergeFrom-com.google.protobuf.ByteString- |
| [`ByteString#toStringUtf8`]: https://developers.google.com/protocol-buffers/docs/reference/java/com/google/protobuf/ByteString#toStringUtf8-- |
| [invalid-utf8-byte-sequences]: https://en.wikipedia.org/wiki/UTF-8#Invalid_byte_sequences |
