def add_pass(self, pss, description=""):
        """
        Append a pass to the PassManager's compilation pipeline
        """
        self._validate_pass(pss)
        func_desc_tuple = (pss, description)
        self.passes.append(func_desc_tuple)
        self._finalized = False

        Append a pass to the PassManager's compilation pipeline
        
numba/core/compiler_machinery.py