    # File lib/fog/aws/elb.rb, line 78
            def initialize(options={})
              @use_iam_profile = options[:use_iam_profile]
              setup_credentials(options)

              @region = options[:region] || 'us-east-1'

              unless ['ap-northeast-1', 'ap-southeast-1', 'ap-southeast-2', 'eu-west-1', 'us-east-1', 'us-west-1', 'us-west-2'].include?(@region)
                raise ArgumentError, "Unknown region: #{@region.inspect}"
              end
            end