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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 _check(self, mode=None):
 """Check if TarFile is still open, and if the operation's mode corresponds to TarFile's mode. """

        if self.closed:
            raise IOError("%s is closed" % self.__class__.__name__)
        if mode is not None and self.mode not in mode:
            raise IOError("bad operation for mode %r" % self.mode)