Create MediaItem from dash manifest string

Previously we could do something like the below to play a video using the dash manifest string:

private fun createDashMediaSource(
        factory: OkHttpDataSource.Factory,
        manifestString: String,
        tag: String? = null,
    ) = DashMediaSource.Factory(factory)
        .createMediaSource(
            createDashManifest(manifestString),
            MediaItem.Builder()
                .setUri(Uri.EMPTY)
                .setMediaId(DashMediaSource.DEFAULT_MEDIA_ID)
                .setMimeType(MimeTypes.APPLICATION_MPD)
                .setTag(tag)
                .build(),
        )

What if we want to go with the mediaItem approach and do not specify the media source? Is it possible to set the parsed dash manifest on the MediaItem somehow?