# LibTmux.SplitPaneRequest.ExpectedWindowId

- **Module:** LibTmux
- **Package:** LibTmux
- **Language:** C#
- **Kind:** property
- **Source:** https://github.com/libtmux/libtmux-dotnet/blob/cf34b255c896d19a97e7d7fabea58609c916012d/src/LibTmux/Requests/SplitPaneRequest.cs#L27
- **Page:** https://libtmux.org/en/csharp/latest/reference/libtmux-splitpanerequest-expectedwindowid/

Gets the window that must contain the target pane at dispatch.

When supplied, a nonwaiting native guard checks the resolved target's
window immediately before splitting. Null keeps ordinary tmux target
semantics. This check does not prevent a later move during readback.