':param fileids: A list specifying the fileids that should be used.
:return: the given file(s) as a list of sentences or utterances,
each encoded as a list of word strings
:rtype: list(list(str))'

def sents(self, fileids=None):

    return concat([MTEFileReader(os.path.join(self._root, f)).sents() for f in self.__fileids(fileids)])
