Extension elements multi type

Hi,

I have problem with extension elements
How can I create configuration with one property has two types.

example:

(...)
extends: [],
isAbstract: false,
properties: [
(...)
{
   isAttr: false,
   isBody: false,
   isMany: true,
   name: "sql",
   > type [{"insert","select"}]
}
(...)
]

I want get xml look like

<bpmn:extensionElements>
  <osdb:Sql>
    <osdb:Insert>
      <osdb:Query1>a</osdb:Query1>
      <osdb:Query2>a</osdb:Query2>
      <osdb:Description>a</osdb:Description>
    </osdb:Insert>
    <osdb:Select>
      <osdb:Query>a</osdb:Query>
      <osdb:Parameter>a</osdb:Parameter>
      <osdb:Parameter>a</osdb:Parameter>
      <osdb:Parameter>a</osdb:Parameter>
      <osdb:Description>a</osdb:Description>
    </osdb:Select>
    <osdb:Insert>
      <osdb:Query1>a</osdb:Query1>
      <osdb:Query2>a</osdb:Query2>
      <osdb:Description>a</osdb:Description>
    </osdb:Insert>
  </osdb:Sql>
</bpmn:extensionElements>