     /// Logging message.
     @discardableResult
     fileprivate func log(message: String?,
+                         writeToFile: Bool = true,
                          filePath: String,
                          function: String,
                          line: Int) -> Logger

        return result
    }
    
    fileprivate func writeToSingleLogFile(_ message: String?,
                                          sourceLocationPrefix: String?)
    {

        }
        
        return self.log(message: message,
                        writeToFile: writeToFile,
                        filePath: filePath,
                        function: function,
                        line: line)
