Fix/format colossalai/engine/paramhooks/(#350)

colossalai/engine/paramhooks/__init__.py

 from ._param_hookmgr import BaseParamHookMgr
-__all__ = ["BaseParamHookMgr"]
\ No newline at end of file
+
+__all__ = ["BaseParamHookMgr"]

colossalai/engine/paramhooks/_param_hookmgr.py

@@ -2,7 +2,9 @@ from typing import Callable, List
 import torch
 import functools
 
+
 class BaseParamHookMgr(object):
+
     def __init__(self, param_list: List[torch.nn.Parameter]) -> None:
         r"""
         register backward hook on every parameters of module
@@ -10,17 +12,17 @@ class BaseParamHookMgr(object):
         self._param_list = param_list
         self._hook_list = []
 
-    def register_backward_hooks(self, hook_call : Callable) -> None:
+    def register_backward_hooks(self, hook_call: Callable) -> None:
         r"""
-        The hook_call will be called every time a gradient with respect to the a param in self.param_list 
-        is computed. 
+        The hook_call will be called every time a gradient with respect to the a param in self.param_list
+        is computed.
         The hook should have the following signature:
         ```
         hook(param, grad) -> Tensor or None
         ```
         """
         if not torch.is_grad_enabled():
-            return  # don't register grad hooks if grad isn't enabled
+            return    # don't register grad hooks if grad isn't enabled
         for p in self._param_list:
             if p.requires_grad and not hasattr(p, '_base_param_hook'):
                 handle = p.register_hook(functools.partial(hook_call, p))