System.Runtime.Serialization.Json.XmlJsonWriter.WriteEndAttribute C# (CSharp) Method

        public override void WriteEndAttribute()
        {
            if (IsClosed)
            {
                ThrowClosed();
            }
            if (!HasOpenAttribute)
            {
                throw new XmlException(SR.JsonNoMatchingStartAttribute);
            }

            Fx.Assert(!(_isWritingDataTypeAttribute && _isWritingServerTypeAttribute),
                "Can not write type attribute and __type attribute at the same time.");

            if (_isWritingDataTypeAttribute)
            {
                switch (_attributeText)
                {
                    case JsonGlobals.numberString:
                        {
                            ThrowIfServerTypeWritten(JsonGlobals.numberString);
                            _dataType = JsonDataType.Number;
                            break;
                        }
                    case JsonGlobals.stringString:
                        {
                            ThrowIfServerTypeWritten(JsonGlobals.stringString);
                            _dataType = JsonDataType.String;
                            break;
                        }
                    case JsonGlobals.arrayString:
                        {
                            ThrowIfServerTypeWritten(JsonGlobals.arrayString);
                            _dataType = JsonDataType.Array;
                            break;
                        }
                    case JsonGlobals.objectString:
                        {
                            _dataType = JsonDataType.Object;
                            break;
                        }
                    case JsonGlobals.nullString:
                        {
                            ThrowIfServerTypeWritten(JsonGlobals.nullString);
                            _dataType = JsonDataType.Null;
                            break;
                        }
                    case JsonGlobals.booleanString:
                        {
                            ThrowIfServerTypeWritten(JsonGlobals.booleanString);
                            _dataType = JsonDataType.Boolean;
                            break;
                        }
                    default:
                        throw new XmlException(SR.Format(SR.JsonUnexpectedAttributeValue, _attributeText));
                }

                _attributeText = null;
                _isWritingDataTypeAttribute = false;

                if (!IsWritingNameWithMapping || WrittenNameWithMapping)
                {
                    WriteDataTypeServerType();
                }
            }
            else if (_isWritingServerTypeAttribute)
            {
                _serverTypeValue = _attributeText;
                _attributeText = null;
                _isWritingServerTypeAttribute = false;

                // we are writing __type after type="object" (enforced by WSE)
                if ((!IsWritingNameWithMapping || WrittenNameWithMapping) && _dataType == JsonDataType.Object)
                {
                    WriteServerTypeAttribute();
                }
            }
            else if (IsWritingNameAttribute)
            {
                WriteJsonElementName(_attributeText);
                _attributeText = null;
                _nameState = NameState.IsWritingNameWithMapping | NameState.WrittenNameWithMapping;
                WriteDataTypeServerType();
            }
            else if (_isWritingXmlnsAttribute)
            {
                if (!string.IsNullOrEmpty(_attributeText) && _isWritingXmlnsAttributeDefaultNs)
                {
                    throw new ArgumentException(SR.Format(SR.JsonNamespaceMustBeEmpty, _attributeText));
                }

                _attributeText = null;
                _isWritingXmlnsAttribute = false;
                _isWritingXmlnsAttributeDefaultNs = false;
            }
        }