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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def has_translation(self, language_code=None, related_name=None):
 """ Return whether a translation for the given language exists. Defaults to the current language code. .. versionadded 1.2 Added the ``related_name`` parameter. """

        if language_code is None:
            language_code = self._current_language
            if language_code is None:
                raise ValueError(get_null_language_error())

        meta = self._parler_meta._get_extension_by_related_name(related_name)

        try:
            # Check the local cache directly, and the answer is known.
            # NOTE this may also return newly auto created translations which are not saved yet.
            return not is_missing(self._translations_cache[meta.model][language_code])
        except KeyError:
            # If there is a prefetch, will be using that.
            # However, don't assume the prefetch contains all possible languages.
            # With Django 1.8, there are custom Prefetch objects.
            # TODO: improve this, detect whether this is the case.
            if language_code in self._read_prefetched_translations(meta=meta):
                return True

            # Try to fetch from the cache first.
            # If the cache returns the fallback, it means the original does not exist.
            object = get_cached_translation(self, language_code, related_name=related_name, use_fallback=True)
            if object is not None:
                return object.language_code == language_code

            try:
                # Fetch from DB, fill the cache.
                self._get_translated_model(language_code, use_fallback=False, auto_create=False, meta=meta)
            except meta.model.DoesNotExist:
                return False
            else:
                return True