code: public boolean submit(SegmentIndexBuffer sib) {
          if(sib == null) {
              return false;
          }
          
          _sibLookup.remove(sib.getSegmentId());
          return _sibSubmit.offer(sib);
      }
docs: Submits (i.e., offers) the specified segment index buffer if it is not <code>null</code>.
  
  @param sib - the segment index buffer
  @return <code>true</code> if the submission is successful. Otherwise, <code>false</code>.