Add layer test for Case operation

tests/layer_tests/tensorflow_tests/test_tf_Case_op.py

@@ -6,6 +6,9 @@
 
 class TestCaseOp(CommonTFLayerTest):
     def _prepare_input(self, inputs_info):
+        """
+        Prepares input data based on the given input shapes and data types.
+        """
         assert 'cond' in inputs_info
         assert 'input_data' in inputs_info
         inputs_data = {
@@ -14,7 +17,17 @@ def _prepare_input(self, inputs_info):
         }
         return inputs_data
 
-    def create_case_net(self, input_shape, branches, default_branch):
+    def create_case_net(self, input_shape, cond_value):
+        """
+        Creates a TensorFlow model with a Case operation.
+
+        Args:
+            input_shape: Shape of the input tensor.
+            cond_value: The condition value to select the branch.
+
+        Returns:
+            TensorFlow graph definition and None.
+        """
         tf.compat.v1.reset_default_graph()
         with tf.compat.v1.Session() as sess:
             # Inputs
@@ -32,22 +45,27 @@ def branch_fn_2():
 
             # Create Case operation
             case_op = tf.raw_ops.Case(branch_index=cond, branches=branches_fn, output_type=tf.float32)
-
+            tf.identity(case_op, name="output")
+
             tf.compat.v1.global_variables_initializer()
             tf_net = sess.graph_def
 
         return tf_net, None
 
+    # Test parameters
     test_data_basic = [
-        dict(input_shape=[1, 2], branches=2, default_branch=None, cond=True),
-        dict(input_shape=[3, 3], branches=2, default_branch=None, cond=False),
+        dict(input_shape=[1, 2], cond=True),
+        dict(input_shape=[3, 3], cond=False),
     ]
 
     @pytest.mark.parametrize("params", test_data_basic)
     @pytest.mark.precommit_tf_fe
     @pytest.mark.nightly
-    def test_case_op(self, params, ie_device, precision, ir_version, temp_dir, 
+    def test_case_op(self, params, ie_device, precision, ir_version, temp_dir,
                      use_new_frontend, use_old_api):
+        """
+        Executes the test for the Case operation.
+        """
         self._test(*self.create_case_net(**params),
                    ie_device, precision, ir_version, temp_dir=temp_dir,
                    use_new_frontend=use_new_frontend, use_old_api=use_old_api)