public void Constructor_ShouldNotThrow_WhenContextIsNotNull()
        {
            // Arrange
            var contextMock = new Mock <ILibrarySystemEfDbContext>();
            var librarySytemEfDbContextSaveChanges = new LibrarySystemEfDbContextSaveChanges(contextMock.Object);

            // Act & Assert
            Assert.That(librarySytemEfDbContextSaveChanges, Is.Not.Null);
        }
        public void SaveChanges_ShouldBeCalledOnce()
        {
            // Arrange
            var contextMock        = new Mock <ILibrarySystemEfDbContext>();
            var contextSaveChanges = new LibrarySystemEfDbContextSaveChanges(contextMock.Object);

            // Act
            contextSaveChanges.SaveChanges();

            // Assert
            contextMock.Verify(c => c.SaveChanges(), Times.Once);
        }