pass custom query to composeWithElastic

is it somehow possible to add custom queries to the elastic query already when defining the GraphQL objects? I wan't to add a filter to my query to retrieve only Users from elastic which have the flag `isCustomer` set. I couldn't find any doc for this. There seems to be an "opts" fields, but not sure how to use it.

```
const CustomerES = composeWithElastic({
graphqlTypeName: 'UserES',
elasticIndex: 'users',
elasticType: '_doc',
elasticMapping: properties,
elasticClient,
pluralFields: ['orders'],
opts: {
query: {
isCustomer: true,
},
},
});
```

sorry if this question is stupid, I'm just starting GraphQL and elastic ;)