add sample code for summary (#33337)

python/paddle/hapi/model_summary.py

@@ -80,6 +80,23 @@ def summary(net, input_size, dtypes=None):
             params_info = paddle.summary(lenet, (1, 1, 28, 28))
             print(params_info)
 
+            # multi input demo
+            class LeNetMultiInput(LeNet):
+
+                def forward(self, inputs, y):
+                    x = self.features(inputs)
+
+                    if self.num_classes > 0:
+                        x = paddle.flatten(x, 1)
+                        x = self.fc(x + y)
+                    return x
+            
+            lenet_multi_input = LeNetMultiInput()
+
+            params_info = paddle.summary(lenet_multi_input, [(1, 1, 28, 28), (1, 400)], 
+                                        ['float32', 'float32'])
+            print(params_info)
+
     """
     if isinstance(input_size, InputSpec):
         _input_size = tuple(input_size.shape)