Next, when we call the converter convert() method, TF-TRT will convert the graph by replacing TensorRT compatible portions of the graph with TRTEngineOps. For better performance at runtime, the converter build() method can be used for creating the TensorRT execution engine ahead of time. The build() method requires the input data shapes to be known before the optimized TensorRT execution engines are built. If input data shapes are not known then TensorRT execution engine can be built at runtime when the input data is available.