src/transformers/integrations.py/TensorBoardCallback/__init__
class TensorBoardCallback:    def __init__(self, tb_writer=None):
        has_tensorboard = is_tensorboard_available()
        if not has_tensorboard:
            raise RuntimeError(
                "TensorBoardCallback requires tensorboard to be installed. Either update your PyTorch version or"
                " install tensorboardX."
            )
        if has_tensorboard:
            try:
                from torch.utils.tensorboard import SummaryWriter  # noqa: F401

                self._SummaryWriter = SummaryWriter
            except ImportError:
                try:
                    from tensorboardX import SummaryWriter

                    self._SummaryWriter = SummaryWriter
                except ImportError:
                    self._SummaryWriter = None
        else:
            self._SummaryWriter = None
        self.tb_writer = tb_writer