def append_pass(self, pass_name: Text):
        """Append a pass at the end of the current passes in the pipeline."""
        if pass_name not in PASS_REGISTRY:
            raise ValueError(f"The pass {pass_name} is not registered.")
        self._pass_names.append(pass_name)
Append a pass at the end of the current passes in the pipeline.
coremltools/converters/mil/mil/passes/pass_pipeline.py