public int getNumTranslationsFor(String sourceLanguage, String targetLanguage) {
        LRUMap<String, String> translationCache =
                cache.get(buildCacheKeyString(sourceLanguage, targetLanguage));
        if (translationCache == null) {
            return 0;
        } else {
            return translationCache.size();
        }
    }
Get the number of different translations from the source language to the target language
this CachedTranslator has in its cache.

@param sourceLanguage The source language of translation.
@param targetLanguage The target language of translation.
@return The number of translations between source and target.
@since Tika 1.6
tika-translate/src/main/java/org/apache/tika/language/translate/impl/CachedTranslator.java