private void unmapBuffer(final ByteBuffer buffer) {
        if (buffer.isDirect()) {
            try {
                LOGGER.debug("Unmapping buffer {}", buffer);
                ByteBufferSupport.unmap(buffer);
            } catch (Exception e) {
                LOGGER.error("Error releasing direct byte buffer", e);
            }
        }
    }
@param n The number to test
@return True if n is a power of ten, e.g. if n==10
stroom-bytebuffer/src/main/java/stroom/bytebuffer/ByteBufferPoolImpl4.java