Microsoft.CodeAnalysis.ConvertAutoPropertyToFullProperty.AbstractConvertAutoPropertyToFullPropertyCodeRefactoringProvider<TPropertyDeclarationNode, TTypeDeclarationNode, TCodeGenerationContextInfo>.GetFieldNameAsync(Microsoft.CodeAnalysis.Document, Microsoft.CodeAnalysis.IPropertySymbol, Microsoft.CodeAnalysis.CodeStyle.NamingStylePreferencesProvider, System.Threading.CancellationToken)