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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 _GetStatus(self, two_factor=False):
 """Check whether OS Login is installed. Args: two_factor: bool, True if two factor should be enabled. Returns: bool, True if OS Login is installed. """

    params = ['status']
    if two_factor:
      params += ['--twofactor']
    retcode = self._RunOsLoginControl(params)
    if retcode is None:
      if self.oslogin_installed:
        self.logger.warning('OS Login not installed.')
        self.oslogin_installed = False
      return None

    # Prevent log spam when OS Login is not installed.
    self.oslogin_installed = True
    if not os.path.exists(constants.OSLOGIN_NSS_CACHE):
      return False
    return not retcode