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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 memory_write8(self, addr, data, zone=None):
 """Writes bytes to memory of a target system. Args: self (JLink):
 the ``JLink`` instance addr (int):
 start address to write to data (list):
 list of bytes to write zone (str):
 optional memory zone to access Returns: Number of bytes written to target. Raises: JLinkException: on memory access error. """

        return self.memory_write(addr, data, zone, 8)