TypeError: Can't instantiate abstract class IdentityTask
**Describe the bug**
Similar to #496 but for `IdentityTask`


diff --git a/src/graphnet/models/task/task.py b/src/graphnet/models/task/task.py
index 4bcf4417..094071a7 100644
--- a/src/graphnet/models/task/task.py
+++ b/src/graphnet/models/task/task.py
@@ -265,16 +265,40 @@ class IdentityTask(Task):
     """Identity, or trivial, task."""
 
     @save_model_config
-    def __init__(self, nb_outputs: int, *args: Any, **kwargs: Any):
+    def __init__(
+        self,
+        nb_outputs: int,
+        target_labels: Union[List[str], Any],
+        *args: Any,
+        **kwargs: Any,
+    ):
         """Construct IdentityTask.
 
         Return the `nb_outputs` as a direct, affine transformation of the last
         hidden layer.
         """
         self._nb_inputs = nb_outputs
+        self._default_target_labels = (
+            target_labels
+            if isinstance(target_labels, list)
+            else [target_labels]
+        )
+        self._default_prediction_labels = [
+            f"target_{i}_pred" for i in range(len(self._default_target_labels))
+        ]
 
-        # Base class constructor
         super().__init__(*args, **kwargs)
+        # Base class constructor
+
+    @property
+    def default_target_labels(self) -> List[str]:
+        """Return default target labels."""
+        return self._default_target_labels
+
+    @property
+    def default_prediction_labels(self) -> List[str]:
+        """Return default prediction labels."""
+        return self._default_prediction_labels
 
     @property
     def nb_inputs(self) -> int:
['src/graphnet/models/task/task.py']