class Selenium::WebDriver::PortProber

def self.free?(port)
  Platform.interfaces.each do |host|
    begin
      TCPServer.new(host, port).close
    rescue *IGNORED_ERRORS => ex
      WebDriver.logger.debug("port prober could not bind to #{host}:#{port} (#{ex.message})")
      # ignored - some machines appear unable to bind to some of their interfaces
    end
  end
  true
rescue SocketError, Errno::EADDRINUSE
  false
end