docs: public long allocateAndClear(int size)
      throws FileManagerException, 
      IOException, 
      EOFException
      {
          //System.out.println("*** allocateAndClear filename=" + filename + " size=" + size);
          long ret = allocate(size);
          PrimitiveArrayPool.PoolEntry bytePoolEntry = this.htoddc.byteArrayPool.allocate(size);
          byte[] clear = (byte[])bytePoolEntry.getArray();
          //byte[] clear = new byte[size];
          seek(ret);
          write(clear);
          this.htoddc.byteArrayPool.returnToPool(bytePoolEntry);
          //clear = null;
          return ret;
      }