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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _concat_datetimetz(to_concat, name=None):
 """ concat DatetimeIndex with the same tz all inputs must be DatetimeIndex it is used in DatetimeIndex.append also """

    # Right now, internals will pass a List[DatetimeArray] here
    # for reductions like quantile. I would like to disentangle
    # all this before we get here.
    sample = to_concat[0]

    if isinstance(sample, ABCIndexClass):
        return sample._concat_same_dtype(to_concat, name=name)
    elif isinstance(sample, ABCDatetimeArray):
        return sample._concat_same_type(to_concat)