code: def callable_check(func, arg_count=1, arg_value=None, allow_none=False):
          
          if func is None:
              if not allow_none:
                  raise ValueError('callable cannot be None')
          elif not arg_checker(func, *[arg_value for _ in range(arg_count)]):
              raise ValueError('callable %s invalid (for %d arguments)' % (func, arg_count))
docs: Check whether func is callable, with the given number of positional arguments. Returns True if check
             succeeded, False otherwise.