code: def language_model(self,verbose=True):
          
          # use a generator in corpus
          prev = None
          for next_letter in self.corpus.next_tamil_letter():
              # update frequency from corpus
              if prev:
                  self.letter2[prev][next_letter] += 1
                  if ( verbose ) :
                      print(prev)
                      print(next_letter)
                      print( self.letter2[prev][next_letter] )
              prev = next_letter #update always
          return
docs: builds a Tamil bigram letter model