Use AbstractWriter's Metadata setter/accessor

By caching a local Metadata field in setMetadata but not passing it to
the abstract superclass, and not providing a getMetadata implementation,
the getMetadata method would always return null.

Instead we perform our validation in setMetadata and then defer to
super.setMetadata, so that getMetadata will just do the right thing.

src/main/java/io/scif/formats/ImarisFormat.java

@@ -77,8 +77,6 @@ protected String[] makeSuffixArray() {
 
 	public static class Writer extends AbstractWriter<DefaultMetadata> {
 
-		private Metadata metadata;
-
 		private ImarisWriter imsWriter;
 		private String path;
 		private int bitDepth;
@@ -94,7 +92,6 @@ public static class Writer extends AbstractWriter<DefaultMetadata> {
 		// writer.setDest(destination, config);
 		@Override
 		public void setMetadata(final Metadata meta) throws FormatException {
-			metadata = meta;
 			// read metadata for writer initialization
 			bitDepth = meta.get(0).getBitsPerPixel();
 			sizeX = meta.get(0).getAxisLength(Axes.X);
@@ -110,6 +107,8 @@ public void setMetadata(final Metadata meta) throws FormatException {
 			pixelSizeXY = FormatTools.getScale(meta, 0, Axes.X);
 			pixelSizeZ = FormatTools.getScale(meta, 0, Axes.Z);
 
+			super.setMetadata(meta);
+
 //		if (metadata != null && metadata != meta) {
 //			try {
 //				metadata.close();
@@ -202,7 +201,7 @@ protected void initialize(final int imageIndex, final long planeIndex,
 		public void savePlane(final int imageIndex, final long planeIndex,
 			final Plane plane) throws FormatException, IOException
 		{
-			final long[] planeMax = metadata.get(imageIndex).getAxesLengthsPlanar();
+			final long[] planeMax = getMetadata().get(imageIndex).getAxesLengthsPlanar();
 			final long[] planeMin = new long[planeMax.length];
 			savePlane(imageIndex, planeIndex, plane, planeMin, planeMax);
 		}
@@ -223,7 +222,7 @@ public void writePlane(final int imageIndex, final long planeIndex,
 			final Plane plane, final long[] planeMin, final long[] planeMax)
 			throws FormatException, IOException
 		{
-			if (!SCIFIOMetadataTools.wholePlane(imageIndex, metadata, planeMin,
+			if (!SCIFIOMetadataTools.wholePlane(imageIndex, getMetadata(), planeMin,
 				planeMax))
 			{
 				throw new FormatException(