Closure cannot implicitly capture a mutating self paramter //http://stackoverflow.com/questions/41940994/closure-cannot-implicitly-capture-a-mutating-self-paramter/41941810#41941810
//http://stackoverflow.com/questions/41940994/closure-cannot-implicitly-capture-a-mutating-self-paramter/41941810#41941810
private func capture(with block: @escaping () -> ()) { block() }