# `GSLayer metricsKey:state:annotation:defaultKey:`

*Instance Method*

## Declaration

```swift
func metricsKey(_ side: GSMetricNumbers, state: UnsafeMutablePointer<GSMetricsKeysUI>?, annotation: AutoreleasingUnsafeMutablePointer<NSString?>?, defaultKey: String?) -> String
```

```objc
- (NSString *) metricsKey:(GSMetricNumbers) side state:(GSMetricsKeysUI *) state annotation:(NSString **) annotation defaultKey:(NSString *) defaultKey;
```

```python
metricsKey_state_annotation_defaultKey_(side: GSMetricNumbers, state: GSMetricsKeysUI, defaultKey: str) -> tuple[str, str]
```