code: public void clear(int size, int off) {
      if (size%4 != 4) size = (size/4+1)*4;
      next = null;
      previous = null;
      data = new byte[size];
      offset = off;
      for(int i = 0; i < data.length; i++)
        data[i] = 0;
      usableBits = off;
    }
docs: Completely clear this element and use the given size and offset for the
  new data array.
  
  @param size Size of data array to use(in bytes)
  @param off Offset to use for this element. Usablebits will also be set to
  this value.