Implemented ThemeComponent reading/saving in translation layer

Filtration.Tests/Translators/TestThemeComponentListBuilder.cs

@@ -0,0 +1,30 @@
+using System.Windows.Media;
+using Filtration.ObjectModel.BlockItemTypes;
+using Filtration.Translators;
+using NUnit.Framework;
+
+namespace Filtration.Tests.Translators
+{
+    [TestFixture]
+    public class TestThemeComponentListBuilder
+    {
+        [Test]
+        public void AddComponent_ReturnsFirstAddedComponent_WhenComponentAddedTwice()
+        {
+            // Arrange
+
+            var testInputTargetType = typeof (TextColorBlockItem);
+            var testInputComponentName = "testComponent";
+            var testInputColor = new Color();
+
+            var builder = new ThemeComponentListBuilder();
+
+            // Act
+            var firstResult = builder.AddComponent(testInputTargetType, testInputComponentName, testInputColor);
+            var secondResult = builder.AddComponent(testInputTargetType, testInputComponentName, testInputColor);
+
+            // Assert
+            Assert.AreSame(firstResult, secondResult);
+        }
+    }
+}