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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 countbit(self, name, start=None, size=None):
 """ Returns the count of set bits in the value of ``key``. Optional ``start`` and ``size`` paramaters indicate which bytes to consider. Similiar with **Redis.BITCOUNT** :param string name: the key name :param int start: Optional, if start is negative, count from start'th character from the end of string. :param int size: Optional, if size is negative, then that many characters will be omitted from the end of string. :return: the count of the bit 1 :rtype: int True 3 True 3 16 """

        if start is not None and size is not None:
            start = get_integer('start', start)
            size = get_integer('size', size)
            return self.execute_command('countbit', name, start, size)
        elif start is not None:
            start = get_integer('start', start)            
            return self.execute_command('countbit', name, start)
        return self.execute_command('countbit', name)