self.myTableView.tableHeaderView?.frame = CGRectMake(0, 0, screenWidth, 290)

extension UITableView {

    func setTableHeaderView(headerView: UIView?) {
        // set the headerView
        tableHeaderView = headerView

        // check if the passed view is nil
        guard let headerView = headerView else { return }

        // check if the tableHeaderView superview view is nil just to avoid
        // to use the force unwrapping later. In case it fail something really
        // wrong happened
        guard let tableHeaderViewSuperview = tableHeaderView?.superview else {
            assertionFailure("This should not be reached!")
            return
        }

        // force updated layout
        headerView.setNeedsLayout()
        headerView.layoutIfNeeded()

        // set tableHeaderView width
        tableHeaderViewSuperview.addConstraint(headerView.widthAnchor.constraint(equalTo: tableHeaderViewSuperview.widthAnchor, multiplier: 1.0))

        // set tableHeaderView height
        let height = headerView.systemLayoutSizeFitting(UILayoutFittingCompressedSize).height
        tableHeaderViewSuperview.addConstraint(headerView.heightAnchor.constraint(equalToConstant: height))
    }


}