use the new apply_nodes attribute name.

theano/tensor/tests/test_merge.py

@@ -62,8 +62,8 @@ def test_merge_with_weird_eq():
     g = Env([x, y], [x+y])
     MergeOptimizer().optimize(g)
 
-    assert len(g.nodes) == 1
-    node = list(g.nodes)[0]
+    assert len(g.apply_nodes) == 1
+    node = list(g.apply_nodes)[0]
     assert len(node.inputs) == 2
     assert node.inputs[0] is node.inputs[1]
 
@@ -74,8 +74,7 @@ def test_merge_with_weird_eq():
     g = Env([x, y], [x+y])
     MergeOptimizer().optimize(g)
 
-    assert len(g.nodes) == 1
-    node = list(g.nodes)[0]
+    assert len(g.apply_nodes) == 1
+    node = list(g.apply_nodes)[0]
     assert len(node.inputs) == 2
     assert node.inputs[0] is node.inputs[1]
-