code: synchronized boolean remove(BlockInfo blockInfo, 
                                int oldReplicas, 
                                int decommissionedReplicas,
                                int oldExpectedReplicas) {
      int priLevel = getPriority(blockInfo, oldReplicas, 
                                 decommissionedReplicas,
                                 oldExpectedReplicas);
      return remove(blockInfo, priLevel);
    }
docs: /* remove a block from a under replication queue