/** Emit a filter that will match against a single value. */
 private RowFilter createValueMatchFilter(
     FilterAdapterContext context, SingleColumnValueFilter filter) throws IOException {
   ValueFilter valueFilter = createValueFilter(filter);
   return delegateAdapter.adapt(context, valueFilter);
 }
 @Override
 public FilterSupportStatus isFilterSupported(
     FilterAdapterContext context, SingleColumnValueFilter filter) {
   return delegateAdapter.isFilterSupported(context, createValueFilter(filter));
 }