def loginfo(message)
      file, line, function = caller[0].split(':')
      @logger.log('INFO', message, file, function, line.to_i)
      self
    end
def loginfo(message)
      file, line, function = caller[0].split(':')
      @logger.log('INFO', message, file, function, line.to_i)
      self
    end
outputs log message for INFO (INFORMATION).
 @param [String] message message for output
 @return [Node] self