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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 clear(self):
 """Convenience method to reset all the block values to 0 """

        if self._bit_count == 0:
            return

        block = self._qpart.document().begin()
        while block.isValid():
            if self.getBlockValue(block):
                self.setBlockValue(block, 0)
            block = block.next()