code: def split_sentences(tokens):
      
      begin = 0
      for i, token in enumerate(tokens):
          if is_end_of_sentence(tokens, i):
              yield tokens[begin:i+1]
              begin = i+1
      if begin <= len(tokens)-1:
          yield tokens[begin:]
docs: Split sentences (based on tokenised data), returns sentences as a list of lists of tokens, each sentence is a list of tokens