I am trying to open up a new tab using javascript. It doesn't work and I get the error:

[Error] SyntaxError: Unexpected token ':'. Expected ')' to end an argument list.
    (anonymous function)

Here is my code:

function openTab() {
    let myUrl = URL(string: "https://google.com")


    // This grabs the active window.
    SFSafariApplication.getActiveWindow { (activeWindow) in

        // Request a new tab on the active window, with the URL we want.
        activeWindow?.openTab(with: myUrl, makeActiveIfPossible: true, completionHandler: {_ in
        })
    }
}

openTab();

Thanks!