Is there any plan to add a way to customize trace.id ？

Is there any plan to add a way to customize trace.id, like the following:

```
const apm = require('elastic-apm-node').start({
// Override service name from package.json
// Allowed characters: a-z, A-Z, 0-9, -, _, and space
serviceName: 'service',
// Set custom APM Server URL (default: http://localhost:8200)
serverUrl: APM_SERVER_URL,
});

apm.setTransactionName('xxx');

apm.setTraceId(customTraceId); // This
```