human
Solve the following python programming problem given the following code:
def close(self, callback = None) : 
    'Close uv handle

        :type callback: Callable(uv_handle: Handle) or None
        ' 
    if self._close_called : 
        return 
if callback : 
        def cb_wrapper(uv_handle_t) : 
            callback (self) 
            alive.remove (self) 
            self._ffi_cb = None 
            self._ffi_close_cb = None 
else : 
        cb_wrapper = functools.partial (default_close_cb, handle = self) 
self._ffi_close_cb = ffi.callback ('void (*)(uv_handle_t *)', cb_wrapper) 
    libuv.uv_close (self.uv_handle, callback._ffi_close_cb) 
    self._close_called = True 

    
    

    Fix the buggy line: libuv.uv_close (self.uv_handle, callback._ffi_close_cb)
assistant
#Here is Python program to fix the buggy line: libuv.

libuv.uv_close (self.uv_handle, self._ffi_close_cb)