Swift - truncate string to length

    /// Truncates String to given langth
    ///
    /// - Parameter length: Result string will be limited to the given number of characters.
    /// If length is 0 or less - empty string will be returned
    /// - Returns: truncated string.
    func truncateToLength(_ length: Int) -> String {
        if length <= 0 {
            // returns empty string
            return ""
        } else if length < self.characters.count {
            let endIndex = self.index(self.startIndex, offsetBy: length)
            let truncatedString = self.substring(to: endIndex)
            return truncatedString
        } else {
            return self
        }
    }