     
     // Compute this as part of init
     let regex: NSRegularExpression
+    let groupsNames: [String]
     
     /**
      Create a new Step definition with an expression to match against and a function to be

        self.function = function
        self.file = file
        self.line = line
        
        // Just throw here; the test will fail :)
        self.regex = try! NSRegularExpression(pattern: expression, options: .caseInsensitive)
    }

        var namedMatches = [String: String]()

        if #available(iOS 11.0, OSX 10.13, *) {
            groupsNames.forEach { (groupName) in
                let range = match.range(withName: groupName)
                let value = (expression as NSString).substring(with: range)
                debugDescription = (debugDescription as NSString).replacingCharacters(in: range, with: groupName.humanReadableString.lowercased())
