<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def finish(self):
 """Stop coverage, save data to file and set the list of coverage objects to report on."""


        self.unset_env()
        self.cov.stop()
        self.cov.combine()
        self.cov.save()
        node_desc = self.get_node_desc(sys.platform, sys.version_info)
        self.node_descs.add(node_desc)