add test for mutliprocessing

tests/test_tc_computation.py

 import torch
 import unittest
 
-from src.tayloranalysis import extend_model
+from src.tayloranalysis import extend_model, BaseTaylorAnalysis
 
 
-class Polynom(torch.nn.Module):
+class Polynom(torch.nn.Module, BaseTaylorAnalysis):
     def __init__(self):
         torch.nn.Module.__init__(self)
 
@@ -14,7 +14,7 @@ class Polynom(torch.nn.Module):
         return x * y + x * y**2 + y**3
 
 
-class FlippedPolynom(torch.nn.Module):
+class FlippedPolynom(torch.nn.Module, BaseTaylorAnalysis):
     def __init__(self):
         torch.nn.Module.__init__(self)
 
@@ -28,8 +28,8 @@ class TestTCComputation(unittest.TestCase):
     def setUp(self):
         # setup models
         self.models = [
-            extend_model(Polynom)(),
-            extend_model(FlippedPolynom)(),
+            Polynom(),
+            FlippedPolynom(),
         ]
         self.feature_axis = (-1, -2)
 
@@ -75,6 +75,26 @@ class TestTCComputation(unittest.TestCase):
                     # compare result to expected value
                     self.assertAlmostEqual(tc, self.solution_dict[combination])
 
+    def test_coefficients_multiprocessing(self):
+        for combination in self.solution_dict.keys():
+            for _model, _feature_axis, _point in zip(
+                self.models,
+                self.feature_axis,
+                self.points,
+            ):
+                # compute TC
+                tc = _model.get_tc(
+                    "point",
+                    forward_kwargs={"point": _point},
+                    tc_idx_list=[combination],
+                    tctensor_features_axis=_feature_axis,
+                    use_parallelization=3,
+                )
+                tc = tc[combination].item()  # as float
+                with self.subTest(combination=combination, feature_axis=_feature_axis):
+                    # compare result to expected value
+                    self.assertAlmostEqual(tc, self.solution_dict[combination])
+
 
 if __name__ == "__main__":
     # run TestTCComputation