# io.github.libtmux.query.Selections.Selections.exactlyOne

- **Module:** io.github.libtmux.query.Selections.Selections
- **Package:** io.github.libtmux:libtmux
- **Language:** Java
- **Kind:** method
- **Source:** https://github.com/libtmux/libtmux-java/blob/c3517519ee799428a809ce6deb1708c8be289cd1/libtmux/src/main/java/io/github/libtmux/query/Selections.java#L19
- **Page:** https://libtmux.org/reference/java/io-github-libtmux-query-selections-selections-exactlyone/

```
io.github.libtmux.query.Selections.Selections.exactlyOne(matches: Iterable<T>) -> T
```

The single match, or a failure naming which way the count was wrong.