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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 register_name(self, register_index):
 """Retrives and returns the name of an ARM CPU register. Args: self (JLink):
 the ``JLink`` instance register_index (int):
 index of the register whose name to retrieve Returns: Name of the register. """

        result = self._dll.JLINKARM_GetRegisterName(register_index)
        return ctypes.cast(result, ctypes.c_char_p).value.decode()