fix: zeldovich using wrong deprecated base class

vaex/test/dataset.py

@@ -217,6 +217,11 @@ def test_uncertainty_propagation(self):
 		distance_std = ds_1.evaluate("distance_uncertainty")[0]
 		self.assertAlmostEqual(distance_std, distance_std_est,2)
 
+	def test_virtual_column_storage(self):
+		self.dataset.write_meta()
+		ds = vaex.zeldovich()
+		ds.write_meta()
+
 	def test_add_virtual_columns_cartesian_velocities_to_polar(self):
 		if 1:
 			def datasets(x, y, velx, vely):