When first tag contains dot, C# client generated using MultipleClientsFromFirstTagAndOperationNameGenerator is invalid

[romfir]

sample swagger.json
code:

async Task Main()
{
	var document = await OpenApiDocument.FromFileAsync("swagger.json");

	var settings = new CSharpClientGeneratorSettings
	{
		GenerateClientClasses = true,
		GenerateOptionalParameters = true,
		OperationNameGenerator = new MultipleClientsFromFirstTagAndOperationNameGenerator(),
		CSharpGeneratorSettings =
	{
		Namespace = "CustomNameSpace",
		JsonLibrary = CSharpJsonLibrary.SystemTextJson,
		ClassStyle = CSharpClassStyle.Poco,
	},
		UseHttpClientCreationMethod = false,
		DisposeHttpClient = true,
		GenerateSyncMethods = false,
		GeneratePrepareRequestAndProcessResponseAsAsyncMethods = false,
	};

	var generator = new CSharpClientGenerator(document, settings);
	
	var codeGeneratedByNSwag = generator.GenerateFile();
	
	Console.WriteLine(codeGeneratedByNSwag);
}

generated code looks like this which is not a valid C# code

 public partial class Categories.CategoryClient 
    {
    #pragma warning disable 8618 // Set by constructor via BaseUrl property
        private string _baseUrl;
    #pragma warning restore 8618 // Set by constructor via BaseUrl property
        private System.Net.Http.HttpClient _httpClient;
        private static System.Lazy<System.Text.Json.JsonSerializerOptions> _settings = new System.Lazy<System.Text.Json.JsonSerializerOptions>(CreateSerializerSettings, true);

        public Categories.CategoryClient(System.Net.Http.HttpClient httpClient)
        {
            BaseUrl = "https://localhost:56908";
            _httpClient = httpClient;
        }

Error is probably located in GenerateControllerName method, it should somehow handle special characters, probably the best solution to this would be to use Roslyn apis, something like this using Microsoft.CodeAnalysis.CSharp:

public static string CsEscapedIdentifier(string text)
{
	if (!SyntaxFacts.IsValidIdentifier(text))
	{
		text = new string(text.Where(SyntaxFacts.IsIdentifierPartCharacter).ToArray());
		if (!SyntaxFacts.IsIdentifierStartCharacter(text[0]))
			text = "a" + text;
	}
	
	if (SyntaxFacts.GetKeywordKind(text) != SyntaxKind.None || SyntaxFacts.GetContextualKeywordKind(text) != SyntaxKind.None)
		text = "@" + text;
		
	return text;
}

code inspired by this

libraries used:
NJsonSchema.CodeGeneration.CSharp: 11.0.0
NSwag.CodeGeneration.CSharp: 14.0.1
NSwag.Core: 14.0.1