@Override
    public int hashCode() {
      return Objects.hash(keySerializationClass, serializationIdentifier);
    }
Registers a key parser for later use in {@link #parseKey}.

<p>This registers a key serializer which can later be used to serialize a key by calling
{@link #parseKey}. If a parser for the pair {@code (SerializationT,
parser.getObjectIdentifier())} has already been registered, this checks if they are the same.
If they are, the call is ignored, otherwise an exception is thrown.
java_src/src/main/java/com/google/crypto/tink/internal/SerializationRegistry.java