class_docstr: Tokenize a string into individual characters.  If this functionality
  is ever required directly, use ``for char in string``.
code: def span_tokenize(self, s):
      yield from enumerate(range(1, len(s) + 1))
  
file_path: nltk/nltk/tokenize/simple.py
imports: from nltk.tokenize.api import StringTokenizer, TokenizerI
  from nltk.tokenize.util import regexp_span_tokenize, string_span_tokenize
label_desc: Use image node_id 2 for calling the CharTokenizer obj's underlying member method code with example usage: obj.span_tokenize(s) without return types