# FilterExpr.validate()

- **Module:** FilterExpr
- **Package:** libtmux-swift
- **Language:** Swift
- **Kind:** method
- **Source:** https://github.com/libtmux/libtmux-swift/blob/f02a4668570e1cc5198c941413750e021f42c214/Sources/LibTmux/FilterExpr.swift#L223
- **Page:** https://libtmux.org/reference/swift/filterexpr-validate()/

```
FilterExpr.validate()() -> ()
```

Rejects field ids this build does not understand anywhere in the tree.

## Raises

- `FilterValidationError`