```ruby
require 'fog'

module SitemapGenerator
  class S3Adapter

    def initialize(opts = {})
      @aws_access_key_id = opts[:aws_access_key_id] || ENV['AWS_ACCESS_KEY_ID']
      @aws_secret_access_key = opts[:aws_secret_access_key] || ENV['AWS_SECRET_ACCESS_KEY']
      @fog_provider = opts[:fog_provider] || ENV['FOG_PROVIDER']
      @fog_directory = opts[:fog_directory] || ENV['FOG_DIRECTORY']
      @fog_region = opts[:fog_region] || ENV['FOG_REGION']
    end

    # Call with a SitemapLocation and string data
    def write(location, raw_data)
      SitemapGenerator::FileAdapter.new.write(location, raw_data)

      credentials = { 
        :aws_access_key_id     => @aws_access_key_id,
        :aws_secret_access_key => @aws_secret_access_key,
        :provider              => @fog_provider,
      }
      credentials[:region] = @fog_region if @fog_region

      storage   = Fog::Storage.new(credentials)
      directory = storage.directories.get(@fog_directory)
      directory.files.create(
        :key    => location.path_in_public,
        :body   => File.open(location.path),
        :public => true
      )
    end

  end
end
```

Allow callers to override the file adapter with an enhanced version
user
```ruby
require 'fog'

module SitemapGenerator
  class S3Adapter

    def initialize(opts = {})
      @aws_access_key_id = opts[:aws_access_key_id] || ENV['AWS_ACCESS_KEY_ID']
      @aws_secret_access_key = opts[:aws_secret_access_key] || ENV['AWS_SECRET_ACCESS_KEY']
      @fog_provider = opts[:fog_provider] || ENV['FOG_PROVIDER']
      @fog_directory = opts[:fog_directory] || ENV['FOG_DIRECTORY']
      @fog_region = opts[:fog_region] || ENV['FOG_REGION']
      @file_adapter = opts[:file_adapter] || SitemapGenerator::FileAdapter.new()
    end

    # Call with a SitemapLocation and string data
    def write(location, raw_data)
      #SitemapGenerator::FileAdapter.new.write(location, raw_data)
      @file_adapter.write(location, raw_data)

      credentials = { 
        :aws_access_key_id     => @aws_access_key_id,
        :aws_secret_access_key => @aws_secret_access_key,
        :provider              => @fog_provider,
      }
      credentials[:region] = @fog_region if @fog_region

      storage   = Fog::Storage.new(credentials)
      directory = storage.directories.get(@fog_directory)
      directory.files.create(
        :key    => location.path_in_public,
        :body   => File.open(location.path),
        :public => true
      )
    end

  end
end
```
assistant