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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 code_memory_read(self, addr, num_bytes):
 """Reads bytes from code memory. Note: This is similar to calling ``memory_read`` or ``memory_read8``, except that this uses a cache and reads ahead. This should be used in instances where you want to read a small amount of bytes at a time, and expect to always read ahead. Args: self (JLink):
 the ``JLink`` instance addr (int):
 starting address from which to read num_bytes (int):
 number of bytes to read Returns: A list of bytes read from the target. Raises: JLinkException: if memory could not be read. """

        buf_size = num_bytes
        buf = (ctypes.c_uint8 * buf_size)()
        res = self._dll.JLINKARM_ReadCodeMem(addr, buf_size, buf)
        if res < 0:
            raise errors.JLinkException(res)
        return list(buf)[:res]