diff --git a/Chsword.Excel2Object.Tests/ExcelTest.cs b/Chsword.Excel2Object.Tests/ExcelConvertTest.cs
similarity index 98%
rename from Chsword.Excel2Object.Tests/ExcelTest.cs
rename to Chsword.Excel2Object.Tests/ExcelConvertTest.cs
index d355bc7..61005cf 100644
--- a/Chsword.Excel2Object.Tests/ExcelTest.cs
+++ b/Chsword.Excel2Object.Tests/ExcelConvertTest.cs
@@ -10,7 +10,7 @@
 namespace Chsword.Excel2Object.Tests
 {
     [TestClass]
-    public class ExcelTest : BaseExcelTest
+    public class ExcelConvertTest : BaseExcelTest
     {
         [TestMethod]
         public void ConvertXlsBytesTest()
diff --git a/Chsword.Excel2Object.Tests/ExcelIssue12Test.cs b/Chsword.Excel2Object.Tests/ExcelIssue12Test.cs
index f6cf1c3..3f5652a 100644
--- a/Chsword.Excel2Object.Tests/ExcelIssue12Test.cs
+++ b/Chsword.Excel2Object.Tests/ExcelIssue12Test.cs
@@ -19,7 +19,7 @@ public void EmptyFirstProperty()
             var importer = new ExcelImporter();
             var result = importer.ExcelToObject<ReportModel>(bytes).ToList();
             Console.WriteLine(result.FirstOrDefault());
-            Assert.AreEqual(models.Count, result.Count());
+            Assert.AreEqual(models.Count, result.Count);
             models.AreEqual(result);
         }
 
diff --git a/Chsword.Excel2Object.Tests/ExcelIssue16Test.cs b/Chsword.Excel2Object.Tests/ExcelIssue16Test.cs
index c505415..5ff6635 100644
--- a/Chsword.Excel2Object.Tests/ExcelIssue16Test.cs
+++ b/Chsword.Excel2Object.Tests/ExcelIssue16Test.cs
@@ -10,6 +10,7 @@ namespace Chsword.Excel2Object.Tests
 {
     /// <summary>
     /// for config and formula
+    /// https://github.com/chsword/Excel2Object/issues/16
     /// </summary>
     [TestClass]
     public class ExcelIssue16Test : BaseExcelTest
diff --git a/Chsword.Excel2Object.Tests/BaseFunctionTest.cs b/Chsword.Excel2Object.Tests/Formula/BaseFunctionTest.cs
similarity index 100%
rename from Chsword.Excel2Object.Tests/BaseFunctionTest.cs
rename to Chsword.Excel2Object.Tests/Formula/BaseFunctionTest.cs
diff --git a/Chsword.Excel2Object.Tests/ExpressionConvertConditionTests.cs b/Chsword.Excel2Object.Tests/Formula/ExpressionConvertConditionTests.cs
similarity index 100%
rename from Chsword.Excel2Object.Tests/ExpressionConvertConditionTests.cs
rename to Chsword.Excel2Object.Tests/Formula/ExpressionConvertConditionTests.cs
diff --git a/Chsword.Excel2Object.Tests/ExpressionConvertMathFunctionsTest.cs b/Chsword.Excel2Object.Tests/Formula/ExpressionConvertMathFunctionsTest.cs
similarity index 90%
rename from Chsword.Excel2Object.Tests/ExpressionConvertMathFunctionsTest.cs
rename to Chsword.Excel2Object.Tests/Formula/ExpressionConvertMathFunctionsTest.cs
index f7f0a64..813b30a 100644
--- a/Chsword.Excel2Object.Tests/ExpressionConvertMathFunctionsTest.cs
+++ b/Chsword.Excel2Object.Tests/Formula/ExpressionConvertMathFunctionsTest.cs
@@ -1,6 +1,6 @@
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 
-namespace Chsword.Excel2Object.Tests
+namespace Chsword.Excel2Object.Tests.Formula
 {
     [TestClass]
     public class ExpressionConvertMathFunctionsTests : BaseFunctionTest
diff --git a/Chsword.Excel2Object.Tests/ExpressionConvertReferenceTests.cs b/Chsword.Excel2Object.Tests/Formula/ExpressionConvertReferenceTests.cs
similarity index 97%
rename from Chsword.Excel2Object.Tests/ExpressionConvertReferenceTests.cs
rename to Chsword.Excel2Object.Tests/Formula/ExpressionConvertReferenceTests.cs
index e892982..a3c03cc 100644
--- a/Chsword.Excel2Object.Tests/ExpressionConvertReferenceTests.cs
+++ b/Chsword.Excel2Object.Tests/Formula/ExpressionConvertReferenceTests.cs
@@ -1,6 +1,6 @@
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 
-namespace Chsword.Excel2Object.Tests
+namespace Chsword.Excel2Object.Tests.Formula
 {
     [TestClass]
     public class ExpressionConvertReferenceTests : BaseFunctionTest
diff --git a/Chsword.Excel2Object.Tests/ExpressionConvertStatisticsTests.cs b/Chsword.Excel2Object.Tests/Formula/ExpressionConvertStatisticsTests.cs
similarity index 91%
rename from Chsword.Excel2Object.Tests/ExpressionConvertStatisticsTests.cs
rename to Chsword.Excel2Object.Tests/Formula/ExpressionConvertStatisticsTests.cs
index 347cab9..9dd4e5e 100644
--- a/Chsword.Excel2Object.Tests/ExpressionConvertStatisticsTests.cs
+++ b/Chsword.Excel2Object.Tests/Formula/ExpressionConvertStatisticsTests.cs
@@ -1,6 +1,6 @@
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 
-namespace Chsword.Excel2Object.Tests
+namespace Chsword.Excel2Object.Tests.Formula
 {
     [TestClass]
     public class ExpressionConvertStatisticsTests : BaseFunctionTest
diff --git a/Chsword.Excel2Object.Tests/ExpressionConvertSymbolTests.cs b/Chsword.Excel2Object.Tests/Formula/ExpressionConvertSymbolTests.cs
similarity index 98%
rename from Chsword.Excel2Object.Tests/ExpressionConvertSymbolTests.cs
rename to Chsword.Excel2Object.Tests/Formula/ExpressionConvertSymbolTests.cs
index 09f71ed..77dc43f 100644
--- a/Chsword.Excel2Object.Tests/ExpressionConvertSymbolTests.cs
+++ b/Chsword.Excel2Object.Tests/Formula/ExpressionConvertSymbolTests.cs
@@ -1,6 +1,6 @@
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 
-namespace Chsword.Excel2Object.Tests
+namespace Chsword.Excel2Object.Tests.Formula
 {
     [TestClass]
     public class ExpressionConvertSymbolTests : BaseFunctionTest
diff --git a/Chsword.Excel2Object.Tests/ExpressionConvertTest.cs b/Chsword.Excel2Object.Tests/Formula/ExpressionConvertTest.cs
similarity index 100%
rename from Chsword.Excel2Object.Tests/ExpressionConvertTest.cs
rename to Chsword.Excel2Object.Tests/Formula/ExpressionConvertTest.cs
diff --git a/Chsword.Excel2Object.Tests/ExpressionConvertTextTests.cs b/Chsword.Excel2Object.Tests/Formula/ExpressionConvertTextTests.cs
similarity index 100%
rename from Chsword.Excel2Object.Tests/ExpressionConvertTextTests.cs
rename to Chsword.Excel2Object.Tests/Formula/ExpressionConvertTextTests.cs
diff --git a/Chsword.Excel2Object/ExcelImporter.cs b/Chsword.Excel2Object/ExcelImporter.cs
index af8f3b2..42bf66c 100644
--- a/Chsword.Excel2Object/ExcelImporter.cs
+++ b/Chsword.Excel2Object/ExcelImporter.cs
@@ -125,7 +125,7 @@ internal static IEnumerable<Dictionary<string, object>> InternalExcelToDictionar
             return list;
         }
 
-        internal static IEnumerable<TModel> InternalExcelToObject<TModel>(IEnumerator result)
+        private static IEnumerable<TModel> InternalExcelToObject<TModel>(IEnumerator result)
             where TModel : class, new()
         {
             var dict = ExcelUtil.GetPropertiesAttributesDict<TModel>();
diff --git a/Chsword.Excel2Object/Functions/ColumnCellDictionary.cs b/Chsword.Excel2Object/Functions/ColumnCellDictionary.cs
index 40df676..ca9e3ed 100644
--- a/Chsword.Excel2Object/Functions/ColumnCellDictionary.cs
+++ b/Chsword.Excel2Object/Functions/ColumnCellDictionary.cs
@@ -11,5 +11,7 @@ public ColumnMatrix Matrix(string keyA, int rowA, string keyB, int rowB)
         {
             throw new NotImplementedException();
         }
+
+        public dynamic Model => throw new NotImplementedException();
     }
 }
\ No newline at end of file