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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 sandbox_status(self, vm_name=None):
        '''
        Returns the status of the sandbox mode.

        Possible values are:
        - on
        - off
        - unknown
        - not installed
        '''
        vagrant_sandbox_output = self._run_sandbox_command(['status', vm_name])
        return self._parse_vagrant_sandbox_status(vagrant_sandbox_output)