Optimize frozen TF graph and prepare a stand-alone TensorRT inference engine error

[xiesibo]

root@14cab064210e:/xiesibo/tensorrt-demo-master# python trt_optimize.py
WARNING: Logging before flag parsing goes to stderr.
W0820 07:21:20.667007 140699697792768 deprecation_wrapper.py:119] From /usr/local/lib/python3.5/dist-packages/uff/converters/tensorflow/conversion_helpers.py:18: The name tf.GraphDef is deprecated. Please use tf.compat.v1.GraphDef instead.

W0820 07:21:20.667487 140699697792768 deprecation_wrapper.py:119] From /usr/local/lib/python3.5/dist-packages/uff/converters/tensorflow/conversion_helpers.py:231: The name tf.gfile.GFile is deprecated. Please use tf.io.gfile.GFile instead.

NOTE: UFF has been tested with TensorFlow 1.12.0. Other versions are not guaranteed to work
WARNING: The version of TensorFlow installed on this system is not guaranteed to work with UFF.
W0820 07:21:22.477570 140699697792768 deprecation_wrapper.py:119] From /usr/local/lib/python3.5/dist-packages/graphsurgeon/_utils.py:2: The name tf.NodeDef is deprecated. Please use tf.compat.v1.NodeDef instead.

UFF Version 0.6.3
=== Automatically deduced input nodes ===
[name: "net/input"
op: "Placeholder"
attr {
key: "dtype"
value {
type: DT_FLOAT
}
}
attr {
key: "shape"
value {
shape {
dim {
size: 1
}
dim {
size: 224
}
dim {
size: 224
}
dim {
size: 3
}
}
}
}
]

Using output node net/plate/BiasAdd
Using output node net/blet/BiasAdd
Converting to UFF graph
No. nodes: 92
[TensorRT] ERROR: UFFParser: Validator error: net/plate/BiasAdd: Unsupported operation Identity
***parser <tensorrt.tensorrt.UffParser object at 0x7ff6e677d0d8>
[TensorRT] ERROR: Network must have at least one output
Traceback (most recent call last):
File "trt_optimize.py", line 49, in
f.write(engine.serialize())
AttributeError: 'NoneType' object has no attribute 'serialize'