diff --git a/API_SQLuedo/EntityFramework/ParagraphEntity.cs b/API_SQLuedo/EntityFramework/ParagraphEntity.cs
index 6785189..b7ab14e 100644
--- a/API_SQLuedo/EntityFramework/ParagraphEntity.cs
+++ b/API_SQLuedo/EntityFramework/ParagraphEntity.cs
@@ -37,10 +37,5 @@ public class ParagraphEntity : ContentLessonEntity
         Info = info;
         Query = query;
         Comment = comment;
-    }
-
-    public object FromEntityToModel()
-    {
-        throw new NotImplementedException();
-    }
+    }
 }
\ No newline at end of file
diff --git a/API_SQLuedo/Model/BlackList.cs b/API_SQLuedo/Model/BlackList.cs
index 002b5ba..bce0cf0 100644
--- a/API_SQLuedo/Model/BlackList.cs
+++ b/API_SQLuedo/Model/BlackList.cs
@@ -7,6 +7,9 @@ public class BlackList
 
     public BlackList(string email, DateOnly expirationDate)
     {
+        if (email is null or "")
+            throw new ArgumentException("Email cannot be null or empty");
+        ArgumentOutOfRangeException.ThrowIfLessThan(expirationDate, DateOnly.FromDateTime(DateTime.Now));
         Email = email;
         ExpirationDate = expirationDate;
     }
diff --git a/API_SQLuedo/TestEF/EntitiesTests/ConcreteContentLessonEntity.cs b/API_SQLuedo/TestEF/EntitiesTests/ConcreteContentLessonEntity.cs
new file mode 100644
index 0000000..15789eb
--- /dev/null
+++ b/API_SQLuedo/TestEF/EntitiesTests/ConcreteContentLessonEntity.cs
@@ -0,0 +1,21 @@
+using Entities;
+
+namespace TestEF.EntitiesTests;
+
+public class ConcreteContentLessonEntity : ContentLessonEntity
+{
+    public ConcreteContentLessonEntity(int id, string contentContent, string contentTitle)
+        : base(id, contentContent, contentTitle)
+    {
+    }
+
+    public ConcreteContentLessonEntity(int id, int lessonId, string contentContent, string contentTitle)
+        : base(id, lessonId, contentContent, contentTitle)
+    {
+    }
+
+    public ConcreteContentLessonEntity(string contentContent, string contentTitle)
+        : base(contentContent, contentTitle)
+    {
+    }
+}
\ No newline at end of file
diff --git a/API_SQLuedo/TestEF/EntitiesTests/TestBlackListEntity.cs b/API_SQLuedo/TestEF/EntitiesTests/TestBlackListEntity.cs
new file mode 100644
index 0000000..abc2ad6
--- /dev/null
+++ b/API_SQLuedo/TestEF/EntitiesTests/TestBlackListEntity.cs
@@ -0,0 +1,54 @@
+using Model;
+
+namespace TestEF.EntitiesTests;
+
+public class TestBlackListEntity
+{
+    [Fact]
+    public void Constructor_ShouldSetProperties_WhenCalledWithTwoParameters()
+    {
+        // Arrange
+        string email = "test@example.com";
+        DateOnly expirationDate = DateOnly.FromDateTime(DateTime.Now.AddDays(10));
+
+        // Act
+        var blackList = new BlackList(email, expirationDate);
+
+        // Assert
+        Assert.Equal(email, blackList.Email);
+        Assert.Equal(expirationDate, blackList.ExpirationDate);
+    }
+
+    [Fact]
+    public void Constructor_ShouldThrowArgumentException_WhenEmailIsEmpty()
+    {
+        // Arrange
+        string email = string.Empty;
+        DateOnly expirationDate = DateOnly.FromDateTime(DateTime.Now.AddDays(10));
+
+        // Act & Assert
+        Assert.Throws<ArgumentException>(() => new BlackList(email, expirationDate));
+    }
+
+    [Fact]
+    public void Constructor_ShouldThrowArgumentException_WhenEmailIsNull()
+    {
+        // Arrange
+        string email = null;
+        DateOnly expirationDate = DateOnly.FromDateTime(DateTime.Now.AddDays(10));
+
+        // Act & Assert
+        Assert.Throws<ArgumentException>(() => new BlackList(email, expirationDate));
+    }
+
+    [Fact]
+    public void Constructor_ShouldThrowArgumentOutOfRangeException_WhenExpirationDateIsInThePast()
+    {
+        // Arrange
+        string email = "test@example.com";
+        DateOnly expirationDate = DateOnly.FromDateTime(DateTime.Now.AddDays(-1));
+
+        // Act & Assert
+        Assert.Throws<ArgumentOutOfRangeException>(() => new BlackList(email, expirationDate));
+    }
+}
\ No newline at end of file
diff --git a/API_SQLuedo/TestEF/EntitiesTests/TestContentLessonEntity.cs b/API_SQLuedo/TestEF/EntitiesTests/TestContentLessonEntity.cs
new file mode 100644
index 0000000..6d2bd7e
--- /dev/null
+++ b/API_SQLuedo/TestEF/EntitiesTests/TestContentLessonEntity.cs
@@ -0,0 +1,55 @@
+namespace TestEF.EntitiesTests;
+
+public class TestContentLessonEntity
+{
+    [Fact]
+    public void Constructor_ShouldSetProperties_WhenCalledWithTwoParameters()
+    {
+        // Arrange
+        const string contentContent = "Content";
+        const string contentTitle = "Title";
+
+        // Act
+        var concreteContentLessonEntity = new ConcreteContentLessonEntity(contentContent, contentTitle);
+
+        // Assert
+        Assert.Equal(contentContent, concreteContentLessonEntity.ContentContent);
+        Assert.Equal(contentTitle, concreteContentLessonEntity.ContentTitle);
+    }
+
+    [Fact]
+    public void Constructor_ShouldSetProperties_WhenCalledWithThreeParameters()
+    {
+        // Arrange
+        const int id = 1;
+        const string contentContent = "Content";
+        const string contentTitle = "Title";
+
+        // Act
+        var concreteContentLessonEntity = new ConcreteContentLessonEntity(id, contentContent, contentTitle);
+
+        // Assert
+        Assert.Equal(id, concreteContentLessonEntity.Id);
+        Assert.Equal(contentContent, concreteContentLessonEntity.ContentContent);
+        Assert.Equal(contentTitle, concreteContentLessonEntity.ContentTitle);
+    }
+
+    [Fact]
+    public void Constructor_ShouldSetProperties_WhenCalledWithFourParameters()
+    {
+        // Arrange
+        const int id = 1;
+        const int lessonId = 2;
+        const string contentContent = "Content";
+        const string contentTitle = "Title";
+
+        // Act
+        var concreteContentLessonEntity = new ConcreteContentLessonEntity(id, lessonId, contentContent, contentTitle);
+
+        // Assert
+        Assert.Equal(id, concreteContentLessonEntity.Id);
+        Assert.Equal(lessonId, concreteContentLessonEntity.LessonId);
+        Assert.Equal(contentContent, concreteContentLessonEntity.ContentContent);
+        Assert.Equal(contentTitle, concreteContentLessonEntity.ContentTitle);
+    }
+}
\ No newline at end of file
diff --git a/API_SQLuedo/TestEF/EntitiesTests/TestSolutionEntity.cs b/API_SQLuedo/TestEF/EntitiesTests/TestSolutionEntity.cs
index 5e31571..8808fd1 100644
--- a/API_SQLuedo/TestEF/EntitiesTests/TestSolutionEntity.cs
+++ b/API_SQLuedo/TestEF/EntitiesTests/TestSolutionEntity.cs
@@ -16,7 +16,7 @@ public class TestSolutionEntity
     public void TestDefaultConstructor()
     {
         SolutionEntity solution = new SolutionEntity();
-        Assert.Equal(0,solution.OwnerId);
+        Assert.Equal(0, solution.OwnerId);
         Assert.Null(solution.Owner);
         Assert.Null(solution.MurdererFirstName);
         Assert.Null(solution.MurdererLastName);
@@ -24,12 +24,12 @@ public class TestSolutionEntity
         Assert.Null(solution.MurderWeapon);
         Assert.Null(solution.Explaination);
     }
-    
+
     [Fact]
     public void TestConstructorWithOnlyId()
     {
         SolutionEntity solution = new SolutionEntity(_inquiryId);
-        Assert.Equal(_inquiryId,solution.OwnerId);
+        Assert.Equal(_inquiryId, solution.OwnerId);
         Assert.Null(solution.Owner);
         Assert.Null(solution.MurdererFirstName);
         Assert.Null(solution.MurdererLastName);
@@ -37,30 +37,56 @@ public class TestSolutionEntity
         Assert.Null(solution.MurderWeapon);
         Assert.Null(solution.Explaination);
     }
-    
+
     [Fact]
     public void TestConstructorWithoutOwnerId()
     {
-        SolutionEntity solution = new SolutionEntity(_inquiry,_murdererFirstName,_murdererLastName,_murderPlace,_murderWeapon, _explaination);
-        Assert.Equal(0,solution.OwnerId);
-        Assert.Equal(_inquiry,solution.Owner);
-        Assert.Equal(_murdererFirstName,solution.MurdererFirstName);
-        Assert.Equal(_murdererLastName,solution.MurdererLastName);
-        Assert.Equal(_murderPlace,solution.MurderPlace);
-        Assert.Equal(_murderWeapon,solution.MurderWeapon);
+        SolutionEntity solution = new SolutionEntity(_inquiry, _murdererFirstName, _murdererLastName, _murderPlace,
+            _murderWeapon, _explaination);
+        Assert.Equal(0, solution.OwnerId);
+        Assert.Equal(_inquiry, solution.Owner);
+        Assert.Equal(_murdererFirstName, solution.MurdererFirstName);
+        Assert.Equal(_murdererLastName, solution.MurdererLastName);
+        Assert.Equal(_murderPlace, solution.MurderPlace);
+        Assert.Equal(_murderWeapon, solution.MurderWeapon);
         Assert.Equal(_explaination, solution.Explaination);
     }
-    
+
     [Fact]
     public void TestConstructorWithAllAttributes()
     {
-        SolutionEntity solution = new SolutionEntity(_inquiryId,_inquiry,_murdererFirstName,_murdererLastName,_murderPlace,_murderWeapon, _explaination);
-        Assert.Equal(_inquiryId,solution.OwnerId);
-        Assert.Equal(_inquiry,solution.Owner);
-        Assert.Equal(_murdererFirstName,solution.MurdererFirstName);
-        Assert.Equal(_murdererLastName,solution.MurdererLastName);
-        Assert.Equal(_murderPlace,solution.MurderPlace);
-        Assert.Equal(_murderWeapon,solution.MurderWeapon);
+        SolutionEntity solution = new SolutionEntity(_inquiryId, _inquiry, _murdererFirstName, _murdererLastName,
+            _murderPlace, _murderWeapon, _explaination);
+        Assert.Equal(_inquiryId, solution.OwnerId);
+        Assert.Equal(_inquiry, solution.Owner);
+        Assert.Equal(_murdererFirstName, solution.MurdererFirstName);
+        Assert.Equal(_murdererLastName, solution.MurdererLastName);
+        Assert.Equal(_murderPlace, solution.MurderPlace);
+        Assert.Equal(_murderWeapon, solution.MurderWeapon);
         Assert.Equal(_explaination, solution.Explaination);
     }
+
+    [Fact]
+    public void Constructor_ShouldSetProperties_WhenCalledWithSixParameters()
+    {
+        // Arrange
+        const int ownerId = 1;
+        const string murdererFirstName = "John";
+        const string murdererLastName = "Doe";
+        const string murderPlace = "WhiteHouse";
+        const string murderWeapon = "Nuclear Bomb";
+        const string explanation = "This is an explanation";
+
+        // Act
+        var solutionEntity = new SolutionEntity(ownerId, murdererFirstName, murdererLastName, murderPlace, murderWeapon,
+            explanation);
+
+        // Assert
+        Assert.Equal(ownerId, solutionEntity.OwnerId);
+        Assert.Equal(murdererFirstName, solutionEntity.MurdererFirstName);
+        Assert.Equal(murdererLastName, solutionEntity.MurdererLastName);
+        Assert.Equal(murderPlace, solutionEntity.MurderPlace);
+        Assert.Equal(murderWeapon, solutionEntity.MurderWeapon);
+        Assert.Equal(explanation, solutionEntity.Explaination);
+    }
 }
\ No newline at end of file