def _load_lang_ngrams(self, lang):

        if lang not in self.langs():
            raise RuntimeError("Unsupported language.")

        crubadan_code = self.iso_to_crubadan(lang)
        ngram_file = path.join(self.root, crubadan_code + '-3grams.txt')

        if not path.isfile(ngram_file):
            raise Runtime("No N-gram file found for requested language.")

        counts = FreqDist()
        if PY3:
            f = open(ngram_file, 'r', encoding='utf-8')
        else:
            f = open(ngram_file, 'rU')

        for line in f:
            if PY3:
                data = line.split(' ')
            else:
                data = line.decode('utf8').split(' ')

            ngram = data[1].strip('\n')
            freq = int(data[0])
            
            counts[ngram] = freq
            
        return counts
Returns the DFS tree for the graph starting from start
dataset/ETHPy150Open nltk/nltk/nltk/corpus/reader/crubadan.py/CrubadanCorpusReader._load_lang_ngrams--crossover with--dataset/ETHPy150Open dnlcrl/PyGraphArt/src/graph.py/Graph.DFS