code: private GenericRecord deserialize(Event event, GenericRecord reuse)
        throws EventDeliveryException {
      decoder = DecoderFactory.get().binaryDecoder(event.getBody(), decoder);
      // no checked exception is thrown in the CacheLoader
      DatumReader<GenericRecord> reader = readers.getUnchecked(schema(event));
      try {
        return reader.read(reuse, decoder);
      } catch (IOException ex) {
        throw new EventDeliveryException("Cannot deserialize event", ex);
      }
    }
docs: Not thread-safe.
  
  @param event
  @param reuse
  @return