code: def tokenize(self, text):
          '''
          tokenize function in Tokenizer.
          '''
          start = -1
          tokens = []
          for i, character in enumerate(text):
              if character == ' ' or character == '\t':
                  if start >= 0:
                      word = text[start:i]
                      tokens.append({
                          'word': word,
                          'original_text': word,
                          'char_begin': start,
                          'char_end': i})
                      start = -1
              else:
                  if start < 0:
                      start = i
          if start >= 0:
              tokens.append({
                  'word': text[start:len(text)],
                  'original_text': text[start:len(text)],
                  'char_begin': start,
                  'char_end': len(text)
              })
          return tokenf tokenize(self, text):
          '''
          tokenize function in Tokenizer.
          '''
          start = -1
          tokens = []
          for i, character in enumerate(text):
              if character == ' ' or character == '\t':
                  if start >= 0:
                      word = text[start:i]
                      tokens.append({
                          'word': word,
                          'original_text': word,
                          'char_begin': start,
                          'char_end': i})
                      start = -1
              else:
                  if start < 0:
                      start = i
          if start >= 0:
              tokens.append({
                  'word': text[start:len(text)],
                  'original_text': text[start:len(text)],
                  'char_begin': start,
                  'char_end': len(text)
              })
          return tokens
docs: tokenize function in Tokenizer.