Repository: Azure/azure-sdk-for-net
File: eng/packages/http-client-csharp/generator/Azure.Generator/src/Visitors/XmlSerializableVisitor.cs (C#)

Code before:
    /// <remarks>
    /// This visitor performs the following modifications:
    /// <list type="number">
    ///   <item>
    ///     <description>
    ///       For models with <see cref="InputModelTypeUsage.Xml"/> usage, adds the <see cref="IXmlSerializable"/> interface
    ///       and implements the explicit <c>void IXmlSerializable.WriteXml(XmlWriter writer, string nameHint)</c> method.
    ///     </description>
    ///   </item>
    ///   <item>
    ///     <description>
    ///       Updates the <c>WriteObjectValue</c> extension method in <see cref="ModelSerializationExtensionsDefinition"/>
    ///       to add a case for <see cref="IXmlSerializable"/> in the switch statement.
    ///     </description>
    ///   </item>
    ///   <item>
    ///     <description>
    ///       For models that ONLY support XML serialization (not JSON), updates the implicit <c>RequestContent</c> operator
    ///       to use <see cref="XmlWriterContent"/>.
    ///     </description>
    ///   </item>
    /// </list>
    /// </remarks>
    internal class XmlSerializableVisitor : ScmLibraryVisitor
    {
        private const string WriteXmlMethodName = "WriteXml";
        private const string WriteObjectValueMethodName = "WriteObjectValue";
        private static readonly CSharpType IXmlSerializableType = typeof(IXmlSerializable);
        private static readonly CSharpType RequestContentType = typeof(RequestContent);
        private readonly Dictionary<TypeProvider, InputModelType> _xmlSerializationProviders = [];

        protected override ModelProvider? PreVisitModel(InputModelType model, ModelProvider? type)
        {
            if (model.Usage.HasFlag(InputModelTypeUsage.Xml) && type is not null)
            {
                foreach (var serializationProvider in type.SerializationProviders)
                {
                    _xmlSerializationProviders.TryAdd(serializationProvider, model);
                }
            }

            return type;
        }

        protected override TypeProvider? VisitType(TypeProvider type)
        {
            if (type is MrwSerializationTypeDefinition serializationProvider)
            {
                if (_xmlSerializationProviders.TryGetValue(serializationProvider, out var inputModel))
                {
                    AddIXmlSerializableImplementation(serializationProvider);

Review comment (suggestion):
@copilot lets add a new constant to use as the name of the IXmlSerializable Write method name:

```csharp
private const string IXmlSerializableWriteMethodName = nameof(IXmlSerializable.Write);
private const string WriteMethodName = "WriteXml";
```

Code after:
    /// <remarks>
    /// This visitor performs the following modifications:
    /// <list type="number">
    ///   <item>
    ///     <description>
    ///       For models with <see cref="InputModelTypeUsage.Xml"/> usage, adds the <see cref="IXmlSerializable"/> interface
    ///       and implements the explicit <c>void IXmlSerializable.Write(XmlWriter writer, string nameHint)</c> method.
    ///     </description>
    ///   </item>
    ///   <item>
    ///     <description>
    ///       Updates the <c>WriteObjectValue</c> extension method in <see cref="ModelSerializationExtensionsDefinition"/>
    ///       to add a case for <see cref="IXmlSerializable"/> in the switch statement.
    ///     </description>
    ///   </item>
    ///   <item>
    ///     <description>
    ///       For models that ONLY support XML serialization (not JSON), updates the implicit <c>RequestContent</c> operator
    ///       to use <see cref="XmlWriterContent"/>.
    ///     </description>
    ///   </item>
    /// </list>
    /// </remarks>
    internal class XmlSerializableVisitor : ScmLibraryVisitor
    {
        private const string IXmlSerializableWriteMethodName = nameof(IXmlSerializable.Write);
        private const string WriteMethodName = "WriteXml";
        private const string WriteObjectValueMethodName = "WriteObjectValue";
        private static readonly CSharpType IXmlSerializableType = typeof(IXmlSerializable);
        private static readonly CSharpType RequestContentType = typeof(RequestContent);
        private readonly Dictionary<TypeProvider, InputModelType> _xmlSerializationProviders = [];

        protected override ModelProvider? PreVisitModel(InputModelType model, ModelProvider? type)
        {
            if (model.Usage.HasFlag(InputModelTypeUsage.Xml) && type is not null)
            {
                foreach (var serializationProvider in type.SerializationProviders)
                {
                    _xmlSerializationProviders.TryAdd(serializationProvider, model);
                }
            }

            return type;
        }

        protected override TypeProvider? VisitType(TypeProvider type)
        {
            if (type is MrwSerializationTypeDefinition serializationProvider)
            {
                if (_xmlSerializationProviders.TryGetValue(serializationProvider, out var inputModel))
                {