code: def _extract_argument_signature(sigstr):
      return sigstr[: sigstr.rfind(")")].strip("()")
  
file_path: nnabla/python/src/nnabla/utils/signature_utils.py
imports: import inspect
label_desc: Use image node_id 1 for calling a global function with example usage: _extract_argument_signature(sigstr) and returns: sigstr