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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 append(self, bs):
 """Append a bitstring to the current bitstring. bs -- The bitstring to append. """

        # The offset is a hint to make bs easily appendable.
        bs = self._converttobitstring(bs, offset=(self.len + self._offset) % 8)
        self._append(bs)