Issue with doc and collection

[princekumar036]

<script>
    import { Doc, Collection } from 'sveltefire';
</script>

<Doc ref={'coll/id'} let:data>
    // do something
</Doc>

// or 
 
<Collection ref={'coll'} let:data>
    // do something
</Collection>

Both the components cause the same error: Uncaught (in promise) FirebaseError: Expected first argument to collection() to be a CollectionReference, a DocumentReference or FirebaseFirestore