code: public void addTransformationOrPredicate(String operationName, Object transformationOrPredicate) {
  		DStreamToStreamAdapterFunction incomingFunc = new DStreamToStreamAdapterFunction(operationName, transformationOrPredicate);
  		this.addTransformationOrPredicate(incomingFunc);
  	}
docs: Will add transformation ({@link SerFunction}) or predicate ({@link SerPredicate}) to be
  applied to the last (current) checkpoint.<br>
  To ensure that both (transformation and predicate) cold be represented as a {@link SerFunction},
  this method will wrap provided 'transformationOrPredicate' with {@link DStreamToStreamAdapterFunction}.
  
  @param operationName
  @param transformationOrPredicate