namespace DotTiled.Tests; public class TmxSerializerTests { [Fact] public void TmxSerializerConstructor_ExternalTilesetResolverIsNull_ThrowsArgumentNullException() { // Arrange Func externalTilesetResolver = null!; // Act Action act = () => _ = new TmxSerializer(externalTilesetResolver); // Assert Assert.Throws(act); } [Fact] public void TmxSerializerConstructor_ExternalTilesetResolverIsNotNull_DoesNotThrow() { // Arrange Func externalTilesetResolver = _ => new Tileset(); // Act var tmxSerializer = new TmxSerializer(externalTilesetResolver); // Assert Assert.NotNull(tmxSerializer); } }