Make private

src/Features/CSharp/Portable/ConvertBetweenRegularAndVerbatimString/AbstractConvertBetweenRegularAndVerbatimStringCodeRefactoringProvider.cs

@@ -11,7 +11,6 @@
 using System.Threading.Tasks;
 using Microsoft.CodeAnalysis.CodeActions;
 using Microsoft.CodeAnalysis.CodeRefactorings;
-using Microsoft.CodeAnalysis.CSharp.LanguageServices;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Microsoft.CodeAnalysis.EmbeddedLanguages.VirtualChars;
 using Microsoft.CodeAnalysis.PooledObjects;
@@ -24,8 +23,8 @@ internal abstract class AbstractConvertBetweenRegularAndVerbatimStringCodeRefact
         : CodeRefactoringProvider
         where TStringExpressionSyntax : ExpressionSyntax
     {
-        protected const char OpenBrace = '{';
-        protected const char CloseBrace = '}';
+        private const char OpenBrace = '{';
+        private const char CloseBrace = '}';
         protected const char DoubleQuote = '"';
 
         protected abstract bool IsInterpolation { get; }