winutil/functions/private/Close-WinUtilRunspacePool.ps1

function Close-WinUtilRunspacePool {
    if ($null -eq $sync -or -not $sync.ContainsKey("runspace") -or $null -eq $sync.runspace) {
        return
    }

    try {
        if ($sync.runspace.RunspacePoolStateInfo.State -notin @(
            [System.Management.Automation.Runspaces.RunspacePoolState]::Closed,
            [System.Management.Automation.Runspaces.RunspacePoolState]::Closing,
            [System.Management.Automation.Runspaces.RunspacePoolState]::Broken
        )) {
            $sync.runspace.Close()
        }
    } finally {
        $sync.runspace.Dispose()
        $sync.Remove("runspace")
    }
}