# plan.wire.parse_optional_argument

- **Module:** plan.wire
- **Package:** libtmux
- **Language:** Rust
- **Kind:** function
- **Source:** https://github.com/libtmux/libtmux-rs/blob/8a648c0894dfffc9303583f753b6c8ae01f2fe76/crates/libtmux/src/plan/wire.rs#L115
- **Page:** https://libtmux.org/reference/rs/plan-wire-parse_optional_argument/

```
plan.wire.parse_optional_argument(deserializer: D) -> Result<Option<OsString>, D::Error>
```

Read back an argument a command may omit.