Remove ModelContextManager class. (#861)

Author: jpinner-lyft

docs/release_notes.rst

@@ -39,6 +39,7 @@ Other changes in this release:
 * Add the attribute name to error messages when deserialization fails (#815)
 * Add the table name to error messages for transactional operations (#835)
 * Move ``pynamodb.connection.util.pythonic`` to ``pynamodb.util.snake_to_camel_case`` (#753)
+* Remove ``ModelContextManager`` class (#861)
 
 Contributors to this release:
 

pynamodb/models.py

@@ -44,26 +44,17 @@
 log.addHandler(logging.NullHandler())
 
 
-class ModelContextManager(Generic[_T]):
+class BatchWrite(Generic[_T]):
     """
-    A class for managing batch operations
+    A class for batch writes
     """
-
     def __init__(self, model: Type[_T], auto_commit: bool = True):
         self.model = model
         self.auto_commit = auto_commit
         self.max_operations = BATCH_WRITE_PAGE_LIMIT
         self.pending_operations: List[Dict[str, Any]] = []
         self.failed_operations: List[Any] = []
 
-    def __enter__(self):
-        return self
-
-
-class BatchWrite(ModelContextManager, Generic[_T]):
-    """
-    A class for batch writes
-    """
     def save(self, put_item: _T) -> None:
         """
         This adds `put_item` to the list of pending operations to be performed.
@@ -104,6 +95,9 @@ def delete(self, del_item: _T) -> None:
                 self.commit()
         self.pending_operations.append({"action": DELETE, "item": del_item})
 
+    def __enter__(self):
+        return self
+
     def __exit__(self, exc_type, exc_val, exc_tb):
         """
         This ensures that all pending operations are committed when