code: public JsonTransformer build() {
  		try {
  			return new WrappingTransformer(buildPipe());
  		} catch(Exception e) {
  			throw new RuntimeException("Failed to build pipeline: " + e.getMessage(), e);
  		}
  	}
docs: Build a raw pipeline without a terminating transformer. It is the caller's responsibility to set the final transformer (@see JsonTransformer.setTarget()) and to apply the pipeline to a stream.
  @return