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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 bytes_needed(self):
            '''return number of bytes needed for next parsing stage'''
            if self.native:
                ret = self.native.expected_length - self.buf_len()
            else:
                ret = self.expected_length - self.buf_len()
            
            if ret <= 0:
                return 1
            return ret