code: def from_sexpr(string):
      toks = iter(_tokenize_sexpr(string))
      if next(toks) != "(":
          raise RuntimeError("Error Parsing sexpr string")
      return _within_bracket(toks)
  
imports: import re
  import codecs
  import random
  from collections import Counter
label_desc: Use image node_id 2 for calling the Tree obj's underlying member method code with example usage: obj.from_sexpr(string) and returns: _within_bracket