Should we avoid using DictionaryInterface?

According to DictionaryInterface.java:

/**
 * Note: DictionaryInterface is an internal interface. This should not be public.
 */
public interface DictionaryInterface {
.
.
.
}

I have a lot of extension functions for both Document and Dictionary, and I can use DictionaryInterface instead of these two so I only create a single method. Should we avoid doing this?

e.g.:

fun Document.getDictionaries(key: String): List<Dictionary> {
    return getArray(key)?.filterIsInstance<Dictionary>() ?: listOf()
}

fun Dictionary.getDictionaries(key: String): List<Dictionary> {
    return getArray(key)?.filterIsInstance<Dictionary>() ?: listOf()
}

vs.

fun DictionaryInterface.getDictionaries(key: String): List<Dictionary> {
    return getArray(key)?.filterIsInstance<Dictionary>() ?: listOf()
}

Yes! That is why it says:

This is an internal interface and not part of the public API.

It may change without warning.

Is it not possible to make it package private/actually internal and not public so we can absolutely not use it?

It may be possible and we may, at some point in the future, do that.