adopt allocateFillValueChunk() and chunkKeyEncoding()

Author: brokkoli71

src/main/java/dev/zarr/zarrjava/v2/ArrayMetadata.java

@@ -4,9 +4,11 @@
 import com.fasterxml.jackson.annotation.JsonIgnore;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import dev.zarr.zarrjava.ZarrException;
+import dev.zarr.zarrjava.utils.MultiArrayUtils;
 import dev.zarr.zarrjava.v3.DataType;
 import dev.zarr.zarrjava.v3.chunkkeyencoding.ChunkKeyEncoding;
 import dev.zarr.zarrjava.v3.chunkkeyencoding.Separator;
+import dev.zarr.zarrjava.v3.chunkkeyencoding.V2ChunkKeyEncoding;
 import dev.zarr.zarrjava.v3.codec.Codec;
 import ucar.ma2.Array;
 
@@ -108,14 +110,15 @@ public DataType dataType() {
 
   @Override
   public Array allocateFillValueChunk() {
-    //TODO
-    return null;
+      ucar.ma2.Array outputArray = ucar.ma2.Array.factory(dataType.getMA2DataType(), chunks);
+      MultiArrayUtils.fill(outputArray, parsedFillValue);
+      return outputArray;
   }
 
   @Override
   public ChunkKeyEncoding chunkKeyEncoding() {
-    //TODO
-    return null;
+    Separator separator = dimensionSeparator == null ? Separator.DOT : dimensionSeparator;
+    return new V2ChunkKeyEncoding(new V2ChunkKeyEncoding.Configuration(separator));
   }
 
   @Override

src/test/java/dev/zarr/zarrjava/ZarrTest.java

@@ -697,7 +697,6 @@ public void testMetadataAcceptsEmptyStorageTransformer() throws ZarrException, I
     ));
   }
 
-  // TODO test withBloscCompressor
   @ParameterizedTest
   @CsvSource({"blosclz,noshuffle,0", "lz4,shuffle,6", "lz4hc,bitshuffle,3", "zlib,shuffle,5", "zstd,bitshuffle,9"})
   public void testV2create(String cname, String shuffle, int clevel) throws IOException, ZarrException {