code: @Override
    protected void visitSoyNode(SoyNode node) {
      if (isComputableAsJsExprsVisitor.exec(node)) {
        // Simply generate JS expressions for this node and add them to the current output var.
        jsCodeBuilder.addChunksToOutputVar(genJsExprsVisitor.exec(node));
  
      } else {
        // Need to implement visit*Node() for the specific case.
        throw new UnsupportedOperationException("implement visit*Node for" + node.getKind());
      }
    }
docs: Fallback implementation.