一小段代码理解Fiber

server = Fiber.new do |request|
  puts 'Server Started'
  while(request != 'exit')
    puts "Received request: #{request}"
    request = Fiber.yield Random.rand
  end
end

response = server.resume 'hi'
puts response
response = server.resume 'hello'
puts response
response = server.resume 'exit'
puts response
server.resume '???'