<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def disconnect(self):
 """ This method disconnects an IOM session to allow for reconnecting when switching networks See the Advanced topics section of the doc for details """

        if self.sascfg.mode != 'IOM':
            res = "This method is only available with the IOM access method"
        else:
            res = self._io.disconnect()
        return res