style: appease flake8 docstring requirements

Signed-off-by: Daniel Bluhm <dbluhm@pm.me>

Author: dbluhm

aries_cloudagent/messaging/models/base.py

@@ -140,6 +140,7 @@ def deserialize(
         *,
         unknown: Optional[str] = None,
     ) -> ModelType:
+        """Convert from JSON representation to a model instance."""
         ...
 
     @overload
@@ -151,6 +152,7 @@ def deserialize(
         none2none: Literal[False],
         unknown: Optional[str] = None,
     ) -> ModelType:
+        """Convert from JSON representation to a model instance."""
         ...
 
     @overload
@@ -162,6 +164,7 @@ def deserialize(
         none2none: Literal[True],
         unknown: Optional[str] = None,
     ) -> Optional[ModelType]:
+        """Convert from JSON representation to a model instance."""
         ...
 
     @classmethod
@@ -208,6 +211,7 @@ def serialize(
         as_string: Literal[True],
         unknown: Optional[str] = None,
     ) -> str:
+        """Create a JSON-compatible dict representation of the model instance."""
         ...
 
     @overload
@@ -216,6 +220,7 @@ def serialize(
         *,
         unknown: Optional[str] = None,
     ) -> dict:
+        """Create a JSON-compatible dict representation of the model instance."""
         ...
 
     def serialize(