edited the comment to add more precise description

python/pyspark/streaming_tests.py

@@ -50,8 +50,8 @@ def setUp(self):
         self.ssc = StreamingContext(appName=class_name, duration=Seconds(1))
 
     def tearDown(self):
-        # Do not call StreamingContext.stop directly because we do not wait to shutdown
-        # call back server and py4j client
+        # Do not call pyspark.streaming.context.StreamingContext.stop directly because
+        # we do not wait to shutdowncall back server and py4j client
         self.ssc._jssc.stop()
         self.ssc._sc.stop()
         # Why does it long time to terminaete StremaingContext and SparkContext?
@@ -146,7 +146,7 @@ def _run_stream(self, test_input, test_func, expected_output):
         """Start stream and return the output"""
         # Generate input stream with user-defined input
         test_input_stream = self.ssc._testInputStream(test_input)
-        # Applied test function to stream
+        # Apply test function to stream
         test_stream = test_func(test_input_stream)
         # Add job to get output from stream
         test_stream._test_output(StreamOutput.result)
@@ -160,6 +160,7 @@ def _run_stream(self, test_input, test_func, expected_output):
             if (current_time - start_time) > self.timeout:
                 break
             self.ssc.awaitTermination(50)
+            # check if the output is the same length of expexted output
             if len(expected_output) == len(StreamOutput.result):
                 break
         return StreamOutput.result