docs: public static byte[] convertJavaToText(Object source, MediaType sourceMediaType, MediaType destinationMediaType) {
        if (source == null) return null;
        if (sourceMediaType == null || destinationMediaType == null) {
           throw new NullPointerException("sourceMediaType and destinationMediaType cannot be null!");
        }
        Object decoded = decodeObjectContent(source, sourceMediaType);
  
        if (decoded instanceof byte[]) {
           return convertCharset(source, StandardCharsets.UTF_8, destinationMediaType.getCharset());
        } else {
           String asString = decoded.toString();
           return asString.getBytes(destinationMediaType.getCharset());
        }
     }