add Group.create with Attributes

Author: brokkoli71

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

@@ -2,6 +2,7 @@
 
 import com.fasterxml.jackson.databind.ObjectMapper;
 import dev.zarr.zarrjava.ZarrException;
+import dev.zarr.zarrjava.core.Attributes;
 import dev.zarr.zarrjava.store.FilesystemStore;
 import dev.zarr.zarrjava.store.StoreHandle;
 import dev.zarr.zarrjava.utils.Utils;
@@ -64,14 +65,26 @@ public static Group create(@Nonnull StoreHandle storeHandle) throws IOException,
     return create(storeHandle, new GroupMetadata());
   }
 
+  public static Group create(@Nonnull StoreHandle storeHandle, Attributes attributes) throws IOException, ZarrException {
+    return create(storeHandle, new GroupMetadata(attributes));
+  }
+
   public static Group create(Path path) throws IOException, ZarrException {
     return create(new StoreHandle(new FilesystemStore(path)));
   }
 
+  public static Group create(Path path, Attributes attributes) throws IOException, ZarrException {
+    return create(new StoreHandle(new FilesystemStore(path)), attributes);
+  }
+
   public static Group create(String path) throws IOException, ZarrException {
     return create(Paths.get(path));
   }
 
+  public static Group create(String path, Attributes attributes) throws IOException, ZarrException {
+    return create(Paths.get(path), attributes);
+  }
+
   @Nullable
   public Node get(String key) throws ZarrException {
     StoreHandle keyHandle = storeHandle.resolve(key);
@@ -102,7 +115,7 @@ public String toString() {
   }
 
   @Override
-  public dev.zarr.zarrjava.core.GroupMetadata metadata() {
+  public GroupMetadata metadata() {
     return metadata;
   }
 }

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

@@ -35,8 +35,15 @@ public GroupMetadata() throws ZarrException {
     this(ZARR_FORMAT, null);
   }
 
+  public GroupMetadata(Attributes attributes) throws ZarrException {
+    this(ZARR_FORMAT, attributes);
+  }
+
   @Override
   public @Nonnull Attributes attributes() throws ZarrException {
+    if (attributes == null) {
+      throw new ZarrException("Group attributes have not been set.");
+    }
     return attributes;
   }
 }