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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 _prepare_script(self, dest_dir, program):
 """Copy the script into the destination directory. :param dest_dir: The target directory where the script will be saved. :param program: The script text to be saved. :return: The name of the script file. :rtype: str """

        script_name = ExecutorFiles.PROCESS_SCRIPT
        dest_file = os.path.join(dest_dir, script_name)
        with open(dest_file, 'wt') as dest_file_obj:
            dest_file_obj.write(program)
        os.chmod(dest_file, 0o700)
        return script_name