HITL - Add collaboration episode loader. (facebookresearch#1933)

* Add collaboration episode loader.

* Remove unused object_goal_pairs.

examples/hitl/rearrange_v2/collaboration_episode_loader.py

@@ -0,0 +1,45 @@
+#!/usr/bin/env python3
+
+# Copyright (c) Meta Platforms, Inc. and its affiliates.
+# This source code is licensed under the MIT license found in the
+# LICENSE file in the root directory of this source tree.
+
+import typing
+
+from habitat.datasets.rearrange.rearrange_dataset import RearrangeEpisode
+
+try:
+    from habitat_llm.agent.env import dataset  # noqa: F401
+    from habitat_llm.agent.env.dataset import CollaborationEpisode
+
+    collaboration_episode_enabled = True
+except ImportError:
+    print("Unable to load CollaborationDataset episode format.")
+    collaboration_episode_enabled = False
+
+
+class CollaborationEpisodeData:
+    instruction: str = ""
+
+
+if collaboration_episode_enabled:
+
+    def load_collaboration_episode_data(
+        episode: RearrangeEpisode,
+    ) -> CollaborationEpisodeData:
+        episode_data = CollaborationEpisodeData()
+
+        if not isinstance(episode, CollaborationEpisode):
+            return episode_data
+
+        episode = typing.cast(CollaborationEpisode, episode)
+        episode_data.instruction = episode.instruction
+
+        return episode_data
+
+else:
+
+    def load_collaboration_episode_data(
+        episode: RearrangeEpisode,
+    ) -> CollaborationEpisodeData:
+        return CollaborationEpisodeData()