code: def log (level, message, quiet: false, &block)
        if !quiet && (LEVELS.index(level) >= LEVELS.index(Logger.level))
          synchronize do
            message = message.to_s.colorize(COLORS[level]) if level
            message.split("\n").each do |line|
              STDERR.puts "  " * Logger.indent + @prefix + line
            end
          end
          with_indent(&block) if block
        elsif block
          block.()
        end
      end
docs: Display a log message. The block, if specified, is executed in an indented region after the log message is shown.
   @api private
   @param [Symbol] level the severity level
   @param [#to_s] message the message to display
   @param block a block to execute with an indent after the message is displayed
   @return the value of block, or nil