public void AddFilesAddFilesToProjectSystem()
        {
            // Arrange
            var fileSystem = new MockProjectSystem();
            var files = PackageUtility.CreateFiles(new[] { "A", "B", "C" });

            // Act
            fileSystem.AddFiles(files, String.Empty);

            // Assert
            Assert.True(fileSystem.FileExists("A"));
            Assert.True(fileSystem.FileExists("B"));
            Assert.True(fileSystem.FileExists("C"));
        }