code: def _find_assign_op(token_line) -> Optional[int]:
      """Get the index of the first assignment in the line ('=' not inside brackets)
  
      Note: We don't try to support multiple special assignment (a = b = %foo)
      """
      paren_level = 0
      for i, ti in enumerate(token_line):
          s = ti.string
          if s == "=" and paren_level == 0:
              return i
          if s in {"(", "[", "{"}:
              paren_level += 1
          elif s in {")", "]", "}"}:
              if paren_level > 0:
                  paren_level -= 1
      return None
  
imports: import ast
  from codeop import CommandCompiler, Compile
  import re
  import sys
  import tokenize
  from typing import List, Tuple, Optional, Any
  import warnings
  from IPython.utils import tokenutil
label_desc: Use image node_id 4 for calling a global function with example usage: _find_assign_op(token_line) and returns: None, i