docs: protected final void clear() {
          UnifiedDataPageX curr = getCurrentPage();
  
          for (int ii=0; ii<_buffers.length; ii++) {
              _buffers[ii] = null;
          }
  
          // curr is null when underlying stream is empty.
          if (curr != null)
          {
              _buffers[0] = curr;
              curr.reset(0);
          }
  
          _buffer_count = 0;
          _buffer_current = 0;
      }