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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 selfcheck(tools):
 """Audit the system for issues. :param tools: Tools description. Use elevation.TOOLS to test elevation. """

    msg = []
    for tool_name, check_cli in collections.OrderedDict(tools).items():
        try:
            subprocess.check_output(check_cli, shell=True, stderr=subprocess.STDOUT)
        except subprocess.CalledProcessError:
            msg.append('%r not found or not usable.' % tool_name)
    return '\n'.join(msg) if msg else 'Your system is ready.'