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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 read(self, n):
        '''Reads n bytes into the internal buffer'''
        bytes_wanted = n - self.buffer_length + self.pos + 1
        if bytes_wanted > 0:
            self._buffer_bytes(bytes_wanted)

        end_pos = self.pos + n
        ret = self.buffer[self.pos + 1:end_pos + 1]
        self.pos = end_pos
        return ret