public <Z, R> void register(Class<Z> decodedClass, Class<R> transcodedClass, ResourceTranscoder<Z, R> transcoder) {
        factories.put(new MultiClassKey(decodedClass, transcodedClass), transcoder);
    }
Registers the given {@link ResourceTranscoder} using the given
classes so it can later be retrieved using the given classes.

@param decodedClass The class of the resource that the transcoder transcodes from.
@param transcodedClass The class of the resource that the transcoder transcodes to.
@param transcoder The transcoder.
@param <Z> The type of the resource that the transcoder transcodes from.
@param <R> The type of the resource that the transcoder transcodes to.
core/src/main/java/com/bumptech/glide/load/resource/transcode/TranscoderRegistry.java