- self.assertEqual(self.square1.project_out('x'), self.dropped)
- self.assertEqual(self.square1.project_out('x y'), self.universe)
- self.assertEqual(self.universe.project_out(' '), self.universe)
- self.assertEqual(self.empty.project_out(' '), Empty)
+ self.assertEqual(self.square1.project_out(symbols('x')), self.dropped)
+ self.assertEqual(self.square1.project_out(symbols('x y')), self.universe)
+ self.assertEqual(self.universe.project_out([]), self.universe)
+ self.assertEqual(self.empty.project_out([]), Empty)