Add missing docstrings

comfy_execution/caching.py

@@ -47,6 +47,8 @@ class CacheKeySet(ABC):
         return self.subcache_keys.get(node_id, None)
 
 class Unhashable:
+    """Hashable sentinel used when an input cannot be safely represented."""
+
     def __init__(self):
         """Create a hashable sentinel value for unhashable prompt inputs."""
         self.value = float("NaN")

tests-unit/execution_test/caching_hashable_test.py

@@ -2,6 +2,7 @@ from comfy_execution.caching import Unhashable, to_hashable
 
 
 def test_to_hashable_returns_unhashable_for_cyclic_builtin_containers():
+    """Ensure self-referential built-in containers terminate as Unhashable."""
     cyclic_list = []
     cyclic_list.append(cyclic_list)
 
@@ -13,6 +14,7 @@ def test_to_hashable_returns_unhashable_for_cyclic_builtin_containers():
 
 
 def test_to_hashable_returns_unhashable_when_max_depth_is_reached():
+    """Ensure deeply nested built-in containers stop at the configured depth limit."""
     nested = current = []
     for _ in range(32):
         next_item = []