[iOS] Adding a subview maximized with insets

UIView+AddingSubviews.swift

func addSubviewMaximized(subview: UIView, insets: UIEdgeInsets? = nil) {
    let insets = insets ?? UIEdgeInsetsZero
    let constraints: [NSLayoutConstraint] = [
        subview.leftAnchor.constraintEqualToAnchor(leftAnchor, constant: insets.left),
        subview.leftAnchor.constraintEqualToAnchor(leftAnchor, constant: -insets.right),
        subview.topAnchor.constraintEqualToAnchor(topAnchor, constant: insets.top),
        subview.bottomAnchor.constraintEqualToAnchor(bottomAnchor, constant: -insets.bottom),
        ]

    subview.translatesAutoresizingMaskIntoConstraints = false
    addSubview(subview)

    // Activate all NSLayoutConstraints
    NSLayoutConstraint.activateConstraints(constraints)
}