code: def parse_option_string(s):
      if not isinstance(s, str):
          return None
      options = {}
      for token in s.split(";"):
          pieces = token.split("=")
          if len(pieces) == 1:
              option, value = pieces[0], ""
          elif len(pieces) == 2:
              option, value = pieces
          else:
              raise ValueError(
                  "Plot option string '%s' is malformed." % (s)
              )
          options[option.strip()] = value.strip()
      return options
  
imports: import pyglet.gl
  from sympy.core import S
label_desc: Use image node_id 19 for calling a global function with example usage: parse_option_string(s) and returns: options, None