Uncomment check output in unitest

python/paddle/v2/fluid/tests/test_warpctc_op.py

@@ -178,21 +178,23 @@ class TestWarpCTCOp(OpTest):
         for i in range(batch_size):
             max_sequence_length = max(max_sequence_length,
                                       logits_lod[0][i + 1] - logits_lod[0][i])
-        gradient = np.zeros(
+        self.gradient = np.zeros(
             [max_sequence_length, batch_size, num_classes], dtype="float32")
 
         self.inputs = {
             "Logits": (logits, logits_lod),
             "Label": (labels, labels_lod)
         }
-        self.outputs = {"Loss": loss, "WarpCTCGrad": gradient}
+        self.outputs = {"Loss": loss}
         self.attrs = {"blank": blank, "norm_by_times": norm_by_times}
 
-#    def test_check_output(self):
-#        self.check_output()
+    def test_check_output(self):
+        self.check_output()
 
     def test_check_grad(self):
+        self.outputs['WarpCTCGrad'] = self.gradient
         self.check_grad(["Logits"], "Loss", max_relative_error=0.01)
 
+
 if __name__ == "__main__":
     unittest.main()