parameters: (cls, func, skip_bound_arg=True)
return_statement: return _signature_fromstr(cls, func, s, skip_bound_arg)
docstring: Private helper function to get signature for
      builtin callables.
docstring_summary: Private helper function to get signature for
      builtin callables.
docstring_tokens: Private helper function to get signature for builtin callables .
function: def _signature_from_builtin(cls, func, skip_bound_arg=True):
      """Private helper function to get signature for
      builtin callables.
      """
  
      if not _signature_is_builtin(func):
          raise TypeError("{!r} is not a Python builtin "
                          "function".format(func))
  
      s = getattr(func, "__text_signature__", None)
      if not s:
          raise ValueError("no signature found for builtin {!r}".format(func))
  
      return _signature_fromstr(cls, func, s, skip_bound_arg)
function_tokens: def _signature_from_builtin ( cls , func , skip_bound_arg = True ) : if not _signature_is_builtin ( func ) : raise TypeError ( "{!r} is not a Python builtin " "function" . format ( func ) ) s = getattr ( func , "__text_signature__" , None ) if not s : raise ValueError ( "no signature found for builtin {!r}" . format ( func ) ) return _signature_fromstr ( cls , func , s , skip_bound_arg )