import XCTest


@available(iOS 9.0, OSX 10.11, *)

public extension XCUIElement {

    var isVisible: Bool {
        return exists && !frame.isEmpty && XCUIApplication().windows.element(boundBy: 0).frame.contains(frame)
    }

}

import XCTest


@available(iOS 9.0, OSX 10.11, *)

extension XCUIElement {

    public var isVisible: Bool {
        return exists && !frame.isEmpty && XCUIApplication().windows.element(boundBy: 0).frame.contains(frame)
    }

}

Make public variable instead of extension
Make public variable instead of extension
