@Override
    public boolean equals(Object o) {
      if (!(o instanceof ParserIndex)) {
        return false;
      }
      ParserIndex other = (ParserIndex) o;
      return other.keySerializationClass.equals(keySerializationClass)
          && other.serializationIdentifier.equals(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