You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: flamegraph.rb
    path of file: ./repos/semian/scripts/benchmarks
    
    the code of the file until where you have to start completion: #!/usr/bin/env ruby

# frozen_string_literal: true

# Envronment variable SEMIAN_VERSION have values v0.16.0, HEAD, master, custom-
    
def server(server_port)
  fork do
    trap("TERM") do
      $stderr.puts "Server: kill signal received...shutting down"
      exit
    end
    # We need to include the Content-Type and Content-Length headers
    # to let the client know the size and type of data
    # contained in the response. Note that HTTP is whitespace
    # sensitive, and expects each header line to end with CRLF (i.e. "\r\n")
    response = "success!"
    response_headers_basis =
      "HTTP/1.1 200 OK\r\n" \
        "Content-Type: text/plain\r\n" \
        "Content-Length: #{response.bytesize}\r\n" \
        "Connection: close\r\n\r\n#{response}"

    server = TCPServer.new("127.0.0.1", server_port)
    $stderr.puts "Server: started on #{server_port}..."
    loop do
      Thread.start(server.accept) do |socket|
        # NOTICE: Ignore for now the request!
        # request = socket.gets
        socket.print(response_headers_basis)
        socket.close
      end
    end
  end
end

def bench(target_version, server_port)
  host = "127.0.0.1"

  if target_version
    require "semian"
    require "semian/version"
    require "semian/net_http"
    $stderr.puts "Load Semian #{Semian::VERSION}"

    if ENV.key?("WITH_CIRCUIT_BREAKER_ENABLED")
      $stderr.puts "Enable Circuit breaker for HTTP requests"
      Semian::NetHTTP.semian_configuration = proc do
        {
          name: "mock_server",
          circuit_breaker: true,
          success_threshold: 3,
          error_threshold: 2,
          error_timeout: 5,
          bulkhead: true,
          tickets: 1,
        }
      end

      # Semian.subscribe do |event, resource, scope, adapter|
      #   $stderr.puts "[semian] adapter=#{adapter} scope=#{scope} event=#{event} " \
      #     "resource_name=#{resource.name} resource=#{resource}"
      # end
    end
  end

  # http = Net::HTTP.new(host, server_port)
  # warmup
  100.times do
    http = Net::HTTP.new(host, server_port)
    http.open_timeout = 1
    begin
      http.get("/")
    rescue
      nil
    end
  end