fix handler npe

[rovboyko]

PR corrects the situation when data stream events are assigned to partitions by AddRouteOperator, but control events aren't. This happens because control events can't be distributed on broadcast rule through the DynamicPartitioner.
PR also fixes NPE in testDynamicalStreamSimplePatternMatch().
#64

[pranjal0811]

I like your way of solving this. I do have also the logic for solving this like -

public ExecutionSiddhiStream cql(DataStream<ControlEvent> controlStream) {
   DataStream<Tuple2<StreamRoute, Object>> unionStream = controlStream
                .map(new NamedControlStream(ControlEvent.DEFAULT_INTERNAL_CONTROL_STREAM))
                .broadcast()
                .union(this.toDataStream())
                .transform("add route transform",
                    SiddhiTypeFactory.getStreamTupleTypeInformation(TypeInformation.of(Object.class)),
                    new AddRouteOperator(getCepEnvironment().getDataStreamSchemas()));
DataStream<Tuple2<StreamRoute,Object>> controlEventStream = unionStream.filter(x ->x.f0.isBroadCastPartitioning()) 
DataStream<Tuple2<StreamRoute,Object>> eventStream = unionStream.filter(x -> !(x.f0.isBroadCastPartitioning()))

DataStream<Tuple2<StreamRoute, Object>> partitionedStream = new DataStream<>(
                    eventStream.getExecutionEnvironment(),
                    new PartitionTransformation<>(eventStream.getTransformation(),
                            new DynamicPartitioner()));

return new ExecutionSiddhiStream(partitionedStream.union(controlEventStream), null, getCepEnvironment());

However, I didn't change the AddRouteOperator logic. This thing will also work, I think my approach will be more overhead. Want your thought to it.

[rovboyko]

I compared two solutions if they build the same JobGraphs or not.

The JobGraphs look like the same except:
my solution:

your solution:

So it really has some overhead - not in additional vertexes, but in additional logic in the route transformation operator.

Nevertheless I prefer to not include control events to the stream before the routing. The main advantage - it won't be ambiguous.