public void LoginTest()
      {
          // Act
          HeaderLogic.GoToSignUp();
          AuthenticationLogic.Login(_testFixture.Credentials);

          // Assert
          Assert.True(HeaderLogic.IsLoggedIn(), "Logout button is not displayed!");
      }
      public void LoginWrongPasswordTest()
      {
          // Assign
          var credentials = new Credentials
          {
              Username = _testFixture.Credentials.Username,
              Password = "******"
          };

          // Act
          HeaderLogic.GoToSignUp();
          AuthenticationLogic.Login(credentials);

          // Assert
          Assert.False(HeaderLogic.IsLoggedIn());
      }
      public void LoginWrongUsernameTest()
      {
          // Assign
          var credentials = new Credentials
          {
              Username = "******",
              Password = _testFixture.Credentials.Password
          };

          // Act
          HeaderLogic.GoToSignUp();
          AuthenticationLogic.Login(credentials);

          // Assert
          Assert.False(HeaderLogic.IsLoggedIn());
      }