3476     PyObject *binop;  member
3492                           PyObject *binop, PyObject *initial)  in itertools_accumulate_impl()  argument
3510     if (binop != Py_None) {  in itertools_accumulate_impl()
3511         Py_XINCREF(binop);  in itertools_accumulate_impl()
3512         lz->binop = binop;  in itertools_accumulate_impl()
3525     Py_XDECREF(lz->binop);  in accumulate_dealloc()
3535     Py_VISIT(lz->binop);  in accumulate_traverse()
3564     if (lz->binop == NULL)  in accumulate_next()
3567         newtotal = PyObject_CallFunctionObjArgs(lz->binop, lz->total, val, NULL);  in accumulate_next()
3591                             it, lz->binop?lz->binop:Py_None, Py_None);  in accumulate_reduce()
3605                                    it, lz->binop ? lz->binop : Py_None);  in accumulate_reduce()
3611                             lz->it, lz->binop?lz->binop:Py_None,  in accumulate_reduce()