Amazon.Internal.RegionEndpointProviderV2.RegionEndpoint.GetEndpointForService C# (CSharp) Method

            public Amazon.RegionEndpoint.Endpoint GetEndpointForService(string serviceName, bool dualStack)
            {
                if (!RegionEndpoint.loaded)
                    RegionEndpoint.LoadEndpointDefinitions();

                var rule = GetEndpointRule(serviceName);
                var endpointTemplate = rule["endpoint"].ToString();
                if (dualStack)
                {
                    // We need special handling for S3's s3.amazonaws.com endpoint, which doesn't
                    // support dualstack (need to transform to s3.dualstack.us-east-1.amazonaws.com).
                    // Other endpoints that begin s3-* need to transform to s3.* for dualstack support.
                    // S3's 'external' endpoints do not support dualstack and should not be transformed.
                    if (serviceName.Equals("s3", StringComparison.OrdinalIgnoreCase))
                    {
                        if (endpointTemplate.Equals("s3.amazonaws.com", StringComparison.OrdinalIgnoreCase))
                            endpointTemplate = "s3.dualstack.us-east-1.amazonaws.com";
                        else
                        {
                            var isExternalEndpoint = endpointTemplate.StartsWith("s3-external-", StringComparison.OrdinalIgnoreCase);
                            if (!isExternalEndpoint)
                            {
                                // transform fixed s3-<region> to s3.<region> and then onto s3.dualstack.<region>,
                                // bypassing endpoints that do not start with the expected tags.
                                if (endpointTemplate.StartsWith("s3-", StringComparison.OrdinalIgnoreCase))
                                    endpointTemplate = "s3." + endpointTemplate.Substring(3);

                                if (endpointTemplate.StartsWith("s3.", StringComparison.OrdinalIgnoreCase))
                                    endpointTemplate = endpointTemplate.Replace("s3.", "s3.dualstack.");
                            }
                        }
                    }
                    else
                        endpointTemplate = endpointTemplate.Replace("{region}", "dualstack.{region}");
                }

                var hostName = endpointTemplate.Replace("{region}", this.SystemName).Replace("{service}", serviceName);

                string signatureVersion = null;
                if (rule["signature-version"] != null)
                    signatureVersion = rule["signature-version"].ToString();

                string authRegion;
                if (rule["auth-region"] != null)
                    authRegion = rule["auth-region"].ToString();
                else
                    authRegion = Amazon.Util.AWSSDKUtils.DetermineRegion(hostName);

                if (string.Equals(authRegion, this.SystemName, StringComparison.OrdinalIgnoreCase))
                    authRegion = null;

                return new Amazon.RegionEndpoint.Endpoint(hostName, authRegion, signatureVersion);
            }