Refactor printing config and object printer

ObjectPrinting/BasePrintingConfig.cs

@@ -0,0 +1,16 @@
+using System;
+
+namespace ObjectPrinting
+{
+    public class BasePrintingConfig
+    {
+        protected static readonly Type[] FinalTypes = {
+            typeof(int), 
+            typeof(double),
+            typeof(float),
+            typeof(string),
+            typeof(DateTime), 
+            typeof(TimeSpan)
+        };
+    }
+}

ObjectPrinting/ObjectPrinter.cs

@@ -1,10 +1,7 @@
 namespace ObjectPrinting
 {
-    public class ObjectPrinter
+    public static class ObjectPrinter
     {
-        public static PrintingConfig<T> For<T>()
-        {
-            return new PrintingConfig<T>();
-        }
+        public static PrintingConfig<T> For<T>() => new PrintingConfig<T>();
     }
 }

ObjectPrinting/PrintingConfig.cs

@@ -4,26 +4,17 @@
 
 namespace ObjectPrinting
 {
-    public class PrintingConfig<TOwner>
+    public class PrintingConfig<TOwner> : BasePrintingConfig
     {
-        public string PrintToString(TOwner obj)
-        {
-            return PrintToString(obj, 0);
-        }
+        public string PrintToString(TOwner obj) => PrintToString(obj, 0);
 
         private string PrintToString(object obj, int nestingLevel)
         {
-            //TODO apply configurations
             if (obj == null)
-                return "null" + Environment.NewLine;
+                return $"null{Environment.NewLine}";
 
-            var finalTypes = new[]
-            {
-                typeof(int), typeof(double), typeof(float), typeof(string),
-                typeof(DateTime), typeof(TimeSpan)
-            };
-            if (finalTypes.Contains(obj.GetType()))
-                return obj + Environment.NewLine;
+            if (FinalTypes.Contains(obj.GetType()))
+                return $"{obj}{Environment.NewLine}";
 
             var identation = new string('\t', nestingLevel + 1);
             var sb = new StringBuilder();