docs: private AbstractExpression parseVectorExpression(VoltXMLElement exprNode) {
          ArrayList<AbstractExpression> args = new ArrayList<>();
          for (VoltXMLElement argNode : exprNode.children) {
              assert(argNode != null);
              // recursively parse each argument subtree (could be any kind of expression).
              AbstractExpression argExpr = parseExpressionNode(argNode);
              assert(argExpr != null);
              args.add(argExpr);
          }
  
          VectorValueExpression vve = new VectorValueExpression();
          vve.setValueType(VoltType.VOLTTABLE);
          vve.setArgs(args);
          return vve;
      }