Fix Codacy Warnings (#477)

---------

Co-authored-by: Dario Coscia <dariocos99@gmail.com>

pina/optim/torch_scheduler.py

@@ -1,7 +1,5 @@
 """Module for PINA Torch Optimizer"""
 
-import torch
-
 try:
     from torch.optim.lr_scheduler import LRScheduler  # torch >= 2.0
 except ImportError:
@@ -15,8 +13,20 @@ from .scheduler_interface import Scheduler
 
 
 class TorchScheduler(Scheduler):
+    """
+    TODO
+
+    :param Scheduler: _description_
+    :type Scheduler: _type_
+    """
 
     def __init__(self, scheduler_class, **kwargs):
+        """
+        TODO
+
+        :param scheduler_class: _description_
+        :type scheduler_class: _type_
+        """
         check_consistency(scheduler_class, LRScheduler, subclass=True)
 
         self.scheduler_class = scheduler_class
@@ -24,6 +34,12 @@ class TorchScheduler(Scheduler):
         self._scheduler_instance = None
 
     def hook(self, optimizer):
+        """
+        TODO
+
+        :param optimizer: _description_
+        :type optimizer: _type_
+        """
         check_consistency(optimizer, Optimizer)
         self._scheduler_instance = self.scheduler_class(
             optimizer.instance, **self.kwargs