class Logger

def with_level(severity)

end
logger.debug { "Hello" }
logger.with_level(:debug) do

Adjust the log level during the block execution for the current Fiber only 
def with_level(severity)
  prev, level_override[Fiber.current] = level, Severity.coerce(severity)
  begin
    yield
  ensure
    if prev
      level_override[Fiber.current] = prev
    else
      level_override.delete(Fiber.current)
    end
  end
end