human
Solve the following python programming problem given the following code:
def __init__(self, single_func = None, multiple_func = None, handle_func = None, attrs = None, **kwargs) : 
    super (Action, self).__init__ (** kwargs) 
    self.method = kwargs.get ('method', 'POST') 
    self.requires_input = kwargs.get ('requires_input', True) 
    self.verbose_name = kwargs.get ('verbose_name', self.name.title ()) 
    self.verbose_name_plural = kwargs.get ('verbose_name_plural', ('%ss' % self.verbose_name)) 
    self.allowed_data_types = kwargs.get ('allowed_data_types', []) 
    self.icon = kwargs.get ('icon', None) 
    if attrs : 
        self.attrs.update (attrs) 
if single_func : 
        self.single = single_func 
if multiple_func : 
        self.multiple = multiple_func 
if handle_func : 
        self.handle = handle_func 
has_handler = (hasattr (self, 'handle') and callable (self.handle)) 
    has_single = (hasattr (multiple, 'single') and callable (self.single)) 
    has_multiple = (hasattr (self, 'multiple') and callable (self.multiple)) 
    if (has_handler or has_multiple) : 
        self.handles_multiple = True 
if ((not has_handler) and ((not has_single) or has_multiple)) : 
        cls_name = self.__class__.__name__ 
        raise NotImplementedError (('You must define either a "handle" method or a "single" or "multiple" method on %s.' % cls_name)) 
if (not has_single) : 
        def single(self, data_table, request, object_id) : 
            return self.handle (data_table, request, [object_id]) 
self.single = types.MethodType (single, self) 
if ((not has_multiple) and self.handles_multiple) : 
        def multiple(self, data_table, request, object_ids) : 
            return self.handle (data_table, request, object_ids) 
self.multiple = types.MethodType (multiple, self) 

    
    

    Fix the buggy line: has_single = (hasattr (multiple, 'single') and callable (self.single))
assistant
#Here is Python code to fix the buggy line: has_single = (hasattr (multiple, 'single') and callable (self.

has_single = (hasattr (self, 'single') and callable (self.single))