# Buggy code
def __init__(self, schedulers, durations, save_history=False):
    if not isinstance(schedulers, Sequence) or len(schedulers) < 2:
        raise ValueError(
            "Argument schedulers should be a sequence of more than one parameter schedulers, "
            "but given {}".format(schedulers)
        )

    if not isinstance(durations, Sequence) or not all(
        [isinstance(t, numbers.Integral) for t in durations]
    ):
        raise ValueError(
            "Argument durations should be list/tuple of integers, but given {}".format(
                durations
            )
        )

    if len(schedulers) != len(durations) + 1:
        raise ValueError(
            "Incorrect number schedulers or duration values, given {} and {}".format(
                len(schedulers), len(durations)
            )
        )

    for i, scheduler in enumerate(schedulers):
        if not isinstance(scheduler, ParamScheduler):
            raise TypeError(
                "Value at index {} of schedulers should be a parameter scheduler, "
                "but given {}".format(i, type(scheduler))
            )

    self.schedulers = schedulers
    self.durations = durations
    super(ConcatScheduler, self).__init__(
        optimizer=_get_fake_optimizer(), param_name="", save_history=save_history
    )

    self._scheduler_index = 0
    self._current_scheduler = None
    self._current_duration = None
    self._setup_scheduler()
    self._state_attrs += ["_current_duration", "durations", "_scheduler_index"]


# Traceback (TypeError)
Traceback (most recent call last):
File "tutorials/misc/lr_schedulers.py", line 56, in <module>
lr_values = LRScheduler.simulate_values(num_events=50, lr_scheduler=lr_scheduler)
File "/work/desrozis/Softwares/conda/envs/focus-light/lib/python3.7/site-packages/ignite/contrib/handlers/param_scheduler.py", line 606, in simulate_values
copy_lr_scheduler = LRScheduler._replicate_lr_scheduler(lr_scheduler)
File "/work/desrozis/Softwares/conda/envs/focus-light/lib/python3.7/site-packages/ignite/contrib/handlers/param_scheduler.py", line 627, in _replicate_lr_scheduler
copy_lr_scheduler = lr_scheduler_cls(optimizer=dummy_optimizer, **kwargs)
TypeError: __init__() got an unexpected keyword argument 'T_i'

# Fixed code
def __init__(self, schedulers, durations, save_history=False):
    if not isinstance(schedulers, Sequence) or len(schedulers) < 2:
        raise ValueError(
            "Argument schedulers should be a sequence of more than one parameter schedulers, "
            "but given {}".format(schedulers)
        )

    if not isinstance(durations, Sequence) or not all(
        [isinstance(t, numbers.Integral) for t in durations]
    ):
        raise ValueError(
            "Argument durations should be list/tuple of integers, but given {}".format(
                durations
            )
        )

    if len(schedulers) != len(durations) + 1:
        raise ValueError(
            "Incorrect number schedulers or duration values, given {} and {}".format(
                len(schedulers), len(durations)
            )
        )

    for i, scheduler in enumerate(schedulers):
        if not isinstance(scheduler, ParamScheduler):
            raise TypeError(
                "Value at index {} of schedulers should be a parameter scheduler, "
                "but given {}".format(i, type(scheduler))
            )

    self.schedulers = schedulers
    self.durations = durations

    self.optimizer = self.schedulers[0].optimizer
    if not (all(id(s.optimizer) == id(self.optimizer) for s in self.schedulers)):
        raise ValueError("schedulers should be related to same optimizer")

    # schedulers should have save_history sync with ParamGroupScheduler
    for s in schedulers:
        s.save_history = save_history

    super(ConcatScheduler, self).__init__(
        optimizer=self.optimizer, param_name="", save_history=save_history
    )

    self._scheduler_index = 0
    self._current_scheduler = None
    self._current_duration = None
    self._setup_scheduler()
    self._state_attrs += ["_current_duration", "durations", "_scheduler_index"]