@Override
  protected ByteBuf newDirectBuffer(int initialCapacity, int maxCapacity) {
    return delegate.directBuffer(initialCapacity, maxCapacity);
  }
A pooled ByteBufAllocator that does not prefer direct buffers regardless of platform settings.
<p>
In some cases direct buffers are still required, like IO buffers where the buffer will be used in
conjunction with a native method call, so we cannot force all buffer usage on heap. But we can
strongly prefer it.
hbase-server/src/main/java/org/apache/hadoop/hbase/ipc/HeapByteBufAllocator.java