class_docstr: A corpus reader used to access language An Crubadan n-gram files.
docstr: Load single n-gram language file given the ISO 639-3 language code
  and return its FreqDist
docstr_tok: ["Load","single","n-gram","language","file","given","the","ISO","639-3","language","code","and","return","its","FreqDist"]
code: def _load_lang_ngrams(self, lang):
      """Load single n-gram language file given the ISO 639-3 language code
      and return its FreqDist"""
  
      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 RuntimeError(
              "No N-gram file found for requested language."
          )
  
      counts = FreqDist()
      with open(ngram_file, encoding="utf-8") as f:
          for line in f:
              data = line.split(" ")
  
              ngram = data[1].strip("\n")
              freq = int(data[0])
  
              counts[ngram] = freq
  
      return counts
  
file_path: nltk/nltk/corpus/reader/crubadan.py
imports: import re
  from os import path
  from nltk.corpus.reader import CorpusReader
  from nltk.data import ZipFilePathPointer
  from nltk.probability import FreqDist
label_desc: Use image node_id 7 for calling the CrubadanCorpusReader obj's underlying member method code with example usage: obj._load_lang_ngrams(lang) and returns: counts