Use functools to mark the _check_handler decorator as a wrapper

Using @functools.wrap ensures that docstrings for wrapped functions
are passed through the decorator correctly.

pykafka/broker.py

@@ -17,6 +17,7 @@
 limitations under the License.
 """
 __all__ = ["Broker"]
+import functools
 import logging
 import time
 
@@ -39,6 +40,7 @@
 
 def _check_handler(fn):
     """Ensures that self._req_handler is not None before calling fn"""
+    @functools.wraps(fn)
     def wrapped(self, *args, **kwargs):
         if self._req_handler is None:
             raise SocketDisconnectedError