torch.nn.modules.module.register_module_forward_pre_hook
torch.nn.modules.module.register_module_forward_pre_hook(hook)
Registers a forward pre-hook common to all modules.
Warning:
 This adds global state to the *nn.module* module and it is only
 intended for debugging/profiling purposes.

The hook will be called every time before "forward()" is invoked.
   It should have the following signature:
  hook(module, input) -> None or modified input

The input contains only the positional arguments given to the
   module. Keyword arguments won't be passed to the hooks and only to
   the "forward". The hook can modify the input. User can either
   return a tuple or a single modified value in the hook. We will wrap
   the value into a tuple if a single value is returned(unless that
   value is already a tuple).
This hook has precedence over the specific module hooks registered
   with "register_forward_pre_hook".
Returns: