class ActiveSupport::Cache::MemCacheStore

def initialize(*addresses)

Passing a +Dalli::Client+ instance is deprecated and will be removed. Please pass an address instead.
+MemCacheStore+ will connect to localhost:11211 (the default memcached port).
If no addresses are provided, but ENV['MEMCACHE_SERVERS'] is defined, it will be used instead. Otherwise,

ActiveSupport::Cache::MemCacheStore.new("localhost", "server-downstairs.localnetwork:8229")

in the form of "host_name:port". For example:
addresses. Each address is either a host name, or a host-with-port string
Creates a new +MemCacheStore+ object, with the given memcached server 
def initialize(*addresses)
  addresses = addresses.flatten
  options = addresses.extract_options!
  if options.key?(:cache_nils)
    options[:skip_nil] = !options.delete(:cache_nils)
  end
  super(options)
  unless [String, Dalli::Client, NilClass].include?(addresses.first.class)
    raise ArgumentError, "First argument must be an empty array, address, or array of addresses."
  end
  if addresses.first.is_a?(Dalli::Client)
    ActiveSupport.deprecator.warn(<<~MSG)
      Initializing MemCacheStore with a Dalli::Client is deprecated and will be removed in Rails 7.2.
      Use memcached server addresses instead.
    MSG
    @data = addresses.first
  else
    @mem_cache_options = options.dup
    # The value "compress: false" prevents duplicate compression within Dalli.
    @mem_cache_options[:compress] = false
    (OVERRIDDEN_OPTIONS - %i(compress)).each { |name| @mem_cache_options.delete(name) }
    @data = self.class.build_mem_cache(*(addresses + [@mem_cache_options]))
  end
end