code: protected Object handleOpNoLine(Op.Type type, long id, Object extra) {
          if (LOG.isDebugEnabled())
              LOG.debug("Line {} not found.", hex(id));
          switch (type) {
              case GET_FROM_OWNER:
                  return extra;
              case PUSH:
              case PUSHX:
                  LOG.info("Attempt to push line {}, but line is not in cache. ", hex(id));
                  return null;
              default:
                  return DIDNT_HANDLE;
          }
      }
docs: Called for a LineMessage when the line is not found
  
  @return true if the op was handled - nothing else necessary. false if not, and creating the line is required