src/transformers/debug_utils.py/DebugUnderflowOverflow/analyse_variable
class DebugUnderflowOverflow:    def analyse_variable(self, var, ctx):
        if torch.is_tensor(var):
            self.expand_frame(get_abs_min_max(var, ctx))
            if detect_overflow(var, ctx):
                self.detected_overflow = True
        elif var is None:
            self.expand_frame(f"{'None':>17} {ctx}")
        else:
            self.expand_frame(f"{'not a tensor':>17} {ctx}")