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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 _check_projects(self):
        '''Check projects by last update time'''
        for project in self.projectdb.check_update(self.last_check_projects,
                                                   ['name', 'updatetime']):
            if project['name'] not in self.projects:
                continue
            if project['updatetime'] > self.projects[project['name']]['info'].get('updatetime', 0):
                self._update_project(project['name'])
        self.last_check_projects = time.time()