Added raster write test

+ fixed a small issue for PAM

imageio/imageio-dds/src/test/java/com/twelvemonkeys/imageio/plugins/dds/DDSImageWriterTest.java

@@ -50,11 +50,22 @@ public class DDSImageWriterTest extends ImageWriterAbstractTest<DDSImageWriter>
         );
     }
 
+    @Test
+    void writeRasters() throws IOException {
+        ImageWriter writer = createWriter();
+
+        assertTrue(writer.canWriteRasters());
+
+        // Full tests in super class
+    }
+
     @Test
     void writeMipmap() throws IOException {
         ImageWriter writer = createWriter();
 
         try {
+            assertTrue(writer.canWriteSequence());
+
             List<BufferedImage> testData = getTestData();
             ByteArrayOutputStream buffer = new ByteArrayOutputStream();
             int previousSize = 0;