code: public void addTempBlockMeta(TempBlockMeta tempBlockMeta)
        throws WorkerOutOfSpaceException, BlockAlreadyExistsException {
      StorageDir dir = tempBlockMeta.getParentDir();
      dir.addTempBlockMeta(tempBlockMeta);
    }
docs: Adds a temp block.
  
  @param tempBlockMeta the metadata of the temp block to add
  @throws WorkerOutOfSpaceException when no more space left to hold the block
  @throws BlockAlreadyExistsException when the block already exists