Make EmptyNamespace and OutputXmlSettings static

Rubberduck.SettingsProvider/XmlPersistanceService.cs

@@ -15,10 +15,10 @@ public class XmlPersistanceService<T> : IFilePersistanceService<T> where T : new
         private const string DefaultConfigFile = "rubberduck.config";
         private const string RootElement = "Configuration";
 
-        private readonly XmlSerializerNamespaces _emptyNamespace =
+        private static readonly XmlSerializerNamespaces EmptyNamespace =
             new XmlSerializerNamespaces(new[] { new XmlQualifiedName(string.Empty, string.Empty) });
 
-        private readonly XmlWriterSettings _outputXmlSettings = new XmlWriterSettings
+        private static readonly XmlWriterSettings OutputXmlSettings = new XmlWriterSettings
         {
             Encoding = new UTF8Encoding(false),
             Indent = true,
@@ -72,7 +72,7 @@ public void Save(T toSerialize)
             using (var writer = new StreamWriter(stream))
             {
                 var serializer = new XmlSerializer(type);
-                serializer.Serialize(writer, toSerialize, _emptyNamespace);
+                serializer.Serialize(writer, toSerialize, EmptyNamespace);
                 var settings = XElement.Parse(_outputEncoding.GetString(stream.ToArray()), LoadOptions.SetBaseUri);
                 if (node != null)
                 {
@@ -91,7 +91,7 @@ public void Save(T toSerialize)
                 Directory.CreateDirectory(_rootPath);
             }
 
-            using (var xml = XmlWriter.Create(FilePath, _outputXmlSettings))
+            using (var xml = XmlWriter.Create(FilePath, OutputXmlSettings))
             {
                 doc.WriteTo(xml);
             }