be fired before all existing "forward_pre" hooks on this
           "torch.nn.modules.Module". Otherwise, the provided "hook"
           will be fired after all existing "forward_pre" hooks on
           this "torch.nn.modules.Module". Note that global
           "forward_pre" hooks registered with
           "register_module_forward_pre_hook()" will fire before all
           hooks registered by this method. Default: "False"
     * **with_kwargs** (*bool*) -- If true, the "hook" will be
       passed the kwargs given to the forward function. Default:
       "False"

  Returns:
     a handle that can be used to remove the added hook by calling
     "handle.remove()"

  Return type:
     "torch.utils.hooks.RemovableHandle"

register_full_backward_hook(hook, prepend=False)
  Registers a backward hook on the module.

  The hook will be called every time the gradients with respect to
  a module are computed, i.e. the hook will execute if and only if
