docs: public static String defineExpressionNodeName(Expression e) {
          String nodeName = "expression";
          if (e instanceof Context) {
              nodeName = "context";
          } else if (e instanceof DecisionTable) {
              nodeName = "decisionTable";
          } else if (e instanceof FunctionDefinition) {
              nodeName = "functionDefinition";
          } else if (e instanceof Invocation) {
              nodeName = "invocation";
          } else if (e instanceof LiteralExpression) {
              nodeName = "literalExpression";
          } else if (e instanceof Relation) {
              nodeName = "relation";
          }
          return nodeName;
      }