I have a following JSON schema snippet.

```
  "attributes": {
                "type": "array",
                "minItems": 3,
                "items": {
                    "type": "string",
                    "enum": [
                        "a",
                        "b",
                        "c"
                    ]
                }
            }

```

I want to permit all the documents, which would have at least 3 elements in "attributes" array. Their values must be "a", "b" and "c", but also on top of that I do NOT want to reject documents that may extend that list.
For instance, I'd like the following snippet to be valid:

```
"attributes": ["x", "a", "b", "z", "c"]

```

Currently my validation fails as there are additional values in the array.

Please advise.