public static BlockWritable[] createPropertyBlockArray(List properties) 
{
        int        block_count   =
            (properties.size() + _properties_per_block - 1)
            / _properties_per_block;
        Property[] to_be_written =
            new Property[ block_count * _properties_per_block ];
        System.arraycopy(properties.toArray(new Property[ 0 ]), 0,
                         to_be_written, 0, properties.size());
        for (int j = properties.size(); j <  to_be_written.length; j++)
        {
            // create an instance of an anonymous inner class that
            // extends Property
            to_be_written[ j ] = new Property()
            {
                protected void preWrite()
                {
                }
                public boolean isDirectory()
                {
                    return false;
                }
            };
        }
        BlockWritable[] rvalue = new BlockWritable[ block_count ];
        for (int j = 0; j <  block_count; j++)
        {
            rvalue[ j ] = new PropertyBlock(to_be_written,
                                            j * _properties_per_block);
        }
        return rvalue;
}

Create an array of PropertyBlocks from an array of Property instances, creating empty Property instances to make up any shortfall

  void writeData(OutputStream stream) throws IOException 
{
        for (int j = 0; j <  _properties_per_block; j++)
        {
            _properties[ j ].writeData(stream);
        }
}

Write the block's data to an OutputStream