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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 _handle_double_click(self, event):
 """ Double click with left mouse button focuses the element"""

        if event.get_button()[1] == 1:  # Left mouse button
            path_info = self.tree_view.get_path_at_pos(int(event.x), int(event.y))
            if path_info:  # Valid entry was clicked on
                path = path_info[0]
                iter = self.list_store.get_iter(path)
                model = self.list_store.get_value(iter, self.MODEL_STORAGE_ID)
                selection = self.model.get_state_machine_m().selection
                selection.focus = model