public static <M> BroadcastOperatorSpec<M> createBroadCastOperatorSpec(
      OutputStreamImpl<M> outputStream, String opId) {
    return new BroadcastOperatorSpec<>(outputStream, opId);
  }
Creates a {@link BroadcastOperatorSpec} for the Broadcast operator.
@param outputStream the {@link OutputStreamImpl} to send messages to
@param opId the unique ID of the operator
@param <M> the type of input message
@return the {@link BroadcastOperatorSpec}
samza-core/src/main/java/org/apache/samza/operators/spec/OperatorSpecs.java