# `GSFeatureGenerator updatePrefix:forFont:error:`

*Instance Method*

## Declaration

```swift
func update(_ prefix: GSFeaturePrefix, for font: GSFont) throws
```

```objc
- (BOOL) updatePrefix:(GSFeaturePrefix *) prefix forFont:(GSFont *) font error:(NSError **) error;
```

```python
updatePrefix_forFont_error_(prefix: GSFeaturePrefix, font: GSFont) -> tuple[bool, NSError]
```