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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 set_folder_names(self, folder_names):

 """Set folder names"""

        assert self.root_path is not None
        path_list = [osp.join(self.root_path, dirname)
                     for dirname in folder_names]
        self.proxymodel.setup_filter(self.root_path, path_list)