void moveBlockToHead(BlockInfo b) {
    blockList = b.listRemove(blockList, this);
    blockList = b.listInsert(blockList, this, -1);
  }
void moveBlockToHead ( BlockInfo b ) { blockList = b . listRemove ( blockList , this ) ; blockList = b . listInsert ( blockList , this , - 1 ) ; }
Move block to the head of the list of blocks belonging to the data-node.