How to use the fastai.callbacks.hooks.Hooks function in fastai

def hook_params(modules:Collection[nn.Module])->Hooks:
    return Hooks(modules, lambda m, i, o: total_params(m))

def hook_outputs(modules:Collection[nn.Module], detach:bool=True, grad:bool=False)->Hooks:
    "Return `Hooks` that store activations of all `modules` in `self.stored`"
    return Hooks(modules, _hook_inner, detach=detach, is_forward=not grad)

def on_train_begin(self, **kwargs):
        "Register the `Hooks` on `self.modules`."
        if not self.modules:
            self.modules = [m for m in flatten_model(self.model) if has_params(m)]
        self.hooks = Hooks(self.modules, self.hook)