# `GSLayer keyForAttributeAxisRules`

*Instance Method*

A stable key of the Alternative-layer axis rules.

## Declaration

```swift
func keyForAttributeAxisRules() -> String?
```

```objc
- (NSString *) keyForAttributeAxisRules;
```

```python
keyForAttributeAxisRules() -> str
```

## Discussion

Returns `nil` when the axis-rules attribute is missing or invalid.